MIT chemical engineers have shown that specialized particles can oscillate together, demonstrating a phenomenon known as emergent behavior. Image: Courtesy of the researchers

By Anne Trafton | MIT News Office

Taking advantage of a phenomenon known as emergent behavior in the microscale, MIT engineers have designed simple microparticles that can collectively generate complex behavior, much the same way that a colony of ants can dig tunnels or collect food.

Working together, the microparticles can generate a beating clock that oscillates at a very low frequency. These oscillations can then be harnessed to power tiny robotic devices, the researchers showed.

“In addition to being interesting from a physics point of view, this behavior can also be translated into an on-board oscillatory electrical signal, which can be very powerful in microrobotic autonomy. There are a lot of electrical components that require such an oscillatory input,” says Jingfan Yang, a recent MIT PhD recipient and one of the lead authors of the new study.

The particles used to create the new oscillator perform a simple chemical reaction that allows the particles to interact with each other through the formation and bursting of tiny gas bubbles. Under the right conditions, these interactions create an oscillator that behaves similar to a ticking clock, beating at intervals of a few seconds.

“We’re trying to look for very simple rules or features that you can encode into relatively simple microrobotic machines, to get them to collectively do very sophisticated tasks,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT.

Strano is the senior author of the new paper, which appears in Nature Communications. Along with Yang, Thomas Berrueta, a Northwestern University graduate student advised by Professor Todd Murphey, is a lead author of the study.

Collective behavior

Demonstrations of emergent behavior can be seen throughout the natural world, where colonies of insects such as ants and bees accomplish feats that a single member of the group would never be able to achieve.

“Ants have minuscule brains and they do very simple cognitive tasks, but collectively they can do amazing things. They can forage for food and build these elaborate tunnel structures,” Strano says. “Physicists and engineers like myself want to understand these rules because it means we can make tiny things that collectively do complex tasks.”

In this study, the researchers wanted to design particles that could generate rhythmic movements, or oscillations, with a very low frequency. Until now, building low-frequency micro-oscillators has required sophisticated electronics that are expensive and difficult to design, or specialized materials with complex chemistries.

The simple particles that the researchers designed for this study are discs as small as 100 microns in diameter. The discs, made from a polymer called SU-8, have a platinum patch that can catalyze the breakdown of hydrogen peroxide into water and oxygen.

When the particles are placed at the surface of a droplet of hydrogen peroxide on a flat surface, they tend to travel to the top of the droplet. At this liquid-air interface, they interact with any other particles found there. Each particle produces its own tiny bubble of oxygen, and when two particles come close enough that their bubbles interact, the bubbles pop, propelling the particles away from each other. Then, they begin forming new bubbles, and the cycle repeats over and over.

“One particle by itself stays still and doesn’t do anything interesting, but through teamwork, they can do something pretty amazing and useful, which is actually a difficult thing to achieve at the microscale,” Yang says.

MIT chemical engineers showed that specialized particles can oscillate together, demonstrating a phenomenon known as emergent behavior. At left, two particles oscillate together, and at right, eight particles. Video courtesy of the researchers.

The researchers found that two particles could make a very reliable oscillator, but as more particles were added, the rhythm would get thrown off. However, if they added one particle that was slightly different from the others, that particle could act as a “leader” that reorganized the other particles back into a rhythmic oscillator.

This leader particle is the same size as the other particles but has a slightly larger platinum patch, which enables it to create a larger oxygen bubble. This allows this particle to move to the center of the group, where it coordinates the oscillations of all of the other particles. Using this approach, the researchers found they could create oscillators containing up to at least 11 particles.

Depending on the number of particles, this oscillator beats at a frequency of about 0.1 to 0.3 hertz, which is on the order of the low-frequency oscillators that govern biological functions such as walking and the beating of the heart.

Oscillating current

The researchers also showed that they could use the rhythmic beating of these particles to generate an oscillating electric current. To do that, they swapped out the platinum catalyst for a fuel cell made of platinum and ruthenium or gold. The mechanical oscillation of the particles rhythmically alters the resistance from one end of the fuel cell to the other, which converts the voltage generated by the fuel cell to an oscillating current.

“Like a dripping faucet, catalytic microdiscs floating at a liquid interface use a chemical reaction to drive the periodic growth and release of gas bubbles. The study shows how these oscillatory dynamics can be harnessed for mechanical actuation and electrochemical signaling relevant to microrobotics,” says Kyle Bishop, a professor of chemical engineering at Columbia University, who was not involved in the study.

Generating an oscillating current instead of a constant one could be useful for applications such as powering tiny robots that can walk. The MIT researchers used this approach to show that they could power a microactuator, which was previously used as legs on a tiny walking robot developed by researchers at Cornell University. The original version was powered by a laser that had to be alternately pointed at each set of legs, to manually oscillate the current. The MIT team showed that the on-board oscillating current generated by their particles could drive the cyclic actuation of the microrobotic leg, using a wire to transfer the current from the particles to the actuator.

“It shows that this mechanical oscillation can become an electrical oscillation, and then that electrical oscillation can actually power activities that a robot would do,” Strano says.

One possible application for this kind of system would be to control swarms of tiny autonomous robots that could be used as sensors to monitor water pollution.

The research was funded in part by the U.S. Army Research Office, the U.S. Department of Energy, and the National Science Foundation.

Dr. Akira Kakugo and his team from Hokkaido University in Japan sent us a video presentation of his recent paper ‘Cooperative cargo transportation by a swarm of molecular machines’, published in Science Robotics.

‘Despite the advancements in macro-scale robots, the development of a large number of small-size robots is still challenging, which is crucial to enhance the scalability of swarm robots,’ says Dr. Kakugo. In the paper, researchers showed it is possible to collectively transport molecular cargo by a swarm of artificial molecular robots (engineered systems with biological/molecular sensors, processors and actuators) responding to light.

• PAPER – Cooperative cargo transportation by a swarm of molecular machines. M. Akter, J. J. Keya, K. Kayano, A. M. R. Kabir, D. Inoue, H. Hess, K. Sada, A. Kuzuya, H. Asanuma, and A. Kakugo. Science Robotics, 7(65), p.eabm0677.

By Florian Meyer

How can a blood clot be removed from the brain without any major surgical intervention? How can a drug be delivered precisely into a diseased organ that is difficult to reach? Those are just two examples of the countless innovations envisioned by the researchers in the field of medical microrobotics. Tiny robots promise to fundamentally change future medical treatments: one day, they could move through patient’s vasculature to eliminate malignancies, fight infections or provide precise diagnostic information entirely noninvasively. In principle, so the researchers argue, the circulatory system might serve as an ideal delivery route for the microrobots, since it reaches all organs and tissues in the body.

For such microrobots to be able to perform the intended medical interventions safely and reliably, they must not be larger than a biological cell. In humans, a cell has an average diameter of 25 micrometres – a micrometre is one millionth of a metre. The smallest blood vessels in humans, the capillaries, are even thinner: their average diameter is only 8 micrometres. The microrobots must be correspondingly small if they are to pass through the smallest blood vessels unhindered. However, such a small size also makes them invisible to the naked eye – and science too, has not yet found a technical solution to detect and track the micron-​sized robots individually as they circulate in the body.

Tracking circulating microrobots for the first time

“Before this future scenario becomes reality and microrobots are actually used in humans, the precise visualisation and tracking of these tiny machines is absolutely necessary,” says Paul Wrede, who is a doctoral fellow at the Max Planck ETH Center for Learnings Systems (CLS). “Without imaging, microrobotics is essentially blind,” adds Daniel Razansky, Professor of Biomedical Imaging at ETH Zurich and the University of Zurich and a member of the CLS. “Real-​time, high-​resolution imaging is thus essential for detecting and controlling cell-​sized microrobots in a living organism.” Further, imaging is also a prerequisite for monitoring therapeutic interventions performed by the robots and verifying that they have carried out their task as intended. “The lack of ability to provide real-​time feedback on the microrobots was therefore a major obstacle on the way to clinical application.”

“Without imaging, microrobotics is essentially blind.”

Daniel Razansky

Together with Metin Sitti, a world-​leading microrobotics expert who is also a CLS member as Director at the Max Planck Institute for Intelligent Systems (MPI-​IS) and ETH Professor of Physical Intelligence, and other researchers, the team has now achieved an important breakthrough in efficiently merging microrobotics and imaging. In a study just published in the scientific journal Science Advances, they managed for the first time to clearly detect and track tiny robots as small as five micrometres in real time in the brain vessels of mice using a non-​invasive imaging technique.

The researchers used microrobots with sizes ranging from 5 to 20 micrometres. The tiniest robots are about the size of red blood cells, which are 7 to 8 micrometres in diameter. This size makes it possible for the intravenously injected microrobots to travel even through the thinnest microcapillaries in the mouse brain.

A breakthrough: Tiny circulating microrobots, which are as small as red blood cells (left picture), were visualised one-​by-one in the blood vessels of mice with optoacoustic imaging (right picture). Image: ETH Zurich / Max Planck Institute for Intelligent Systems

The researchers also developed a dedicated optoacoustic tomography technology in order to actually detect the tiny robots one by one, in high resolution and in real time. This unique imaging method makes it possible to detect the tiny robots in deep and hard-​to-reach regions of the body and brain, which would not have been possible with optical microscopy or any other imaging technique. The method is called optoacoustic because light is first emitted and absorbed by the respective tissue. The absorption then produces tiny ultrasound waves that can be detected and analysed to result in high-​resolution volumetric images.

Janus-​faced robots with gold layer

To make the microrobots highly visible in the images, the researchers needed a suitable contrast material. For their study, they therefore used spherical, silica particle-​based microrobots with a so-​called Janus-​type coating. This type of robot has a very robust design and is very well qualified for complex medical tasks. It is named after the Roman god Janus, who had two faces. In the robots, the two halves of the sphere are coated differently. In the current study, the researchers coated one half of the robot with nickel and the other half with gold.

The spherical microrobots consist of silica-based particles and have been coated half with nickel (Ni) and half with gold (Au) and loaded with green-dyed nanobubbles (liposomes). In this way, they can be detected individually with the new optoacoustic imaging technique. Image: ETH Zurich / MPI-IS

“Gold is a very good contrast agent for optoacoustic imaging,” explains Razansky, “without the golden layer, the signal generated by the microrobots is just too weak to be detected.” In addition to gold, the researchers also tested the use of small bubbles called nanoliposomes, which contained a fluorescent green dye that also served as a contrast agent. “Liposomes also have the advantage that you can load them with potent drugs, which is important for future approaches to targeted drug delivery,” says Wrede, the first author of the study. The potential uses of liposomes will be investigated in a follow-​up study.

Furthermore, the gold also allows to minimise the cytotoxic effect of the nickel coating – after all, if in the future microrobots are to operate in living animals or humans, they must be made biocompatible and non-​toxic, which is part of an ongoing research. In the present study, the researchers used nickel as a magnetic drive medium and a simple permanent magnet to pull the robots. In follow-​up studies, they want to test the optoacoustic imaging with more complex manipulations using rotating magnetic fields.

“This would give us the ability to precisely control and move the microrobots even in strongly flowing blood,” says Metin Sitti. “In the present study we focused on visualising the microrobots. The project was tremendously successful thanks to the excellent collaborative environment at the CLS that allowed combining the expertise of the two research groups at MPI-​IS in Stuttgart for the robotic part and ETH Zurich for the imaging part,” Sitti concludes.

• PAPER – Real-​time 3D optoacoustic tracking of cell-​sized magnetic microrobots circulating in the mouse brain vasculature. Wrede P, Degtyaruk O, Kalva SK, Deán-​Ben XL, Bozuyuk U, Aghakhani A, Akolpoglu B, Sitti M, and Razansky D. Science Advances, 11. Mai 2022. DOI: 10.1126/sciadv.abm9132

Front view of the flying robot. Image credit: Dr Tim Helps

This new advance, published in the journal Science Robotics, could pave the way for smaller, lighter and more effective micro flying robots for environmental monitoring, search and rescue, and deployment in hazardous environments.

Until now, typical micro flying robots have used motors, gears and other complex transmission systems to achieve the up-and-down motion of the wings. This has added complexity, weight and undesired dynamic effects.

Taking inspiration from bees and other flying insects, researchers from Bristol’s Faculty of Engineering, led by Professor of Robotics Jonathan Rossiter, have successfully demonstrated a direct-drive artificial muscle system, called the Liquid-amplified Zipping Actuator (LAZA), that achieves wing motion using no rotating parts or gears.

The LAZA system greatly simplifies the flapping mechanism, enabling future miniaturization of flapping robots down to the size of insects.

In the paper, the team show how a pair of LAZA-powered flapping wings can provide more power compared with insect muscle of the same weight, enough to fly a robot across a room at 18 body lengths per second.

They also demonstrated how the LAZA can deliver consistent flapping over more than one million cycles, important for making flapping robots that can undertake long-haul flights.

The team expect the LAZA to be adopted as a fundamental building block for a range of autonomous insect-like flying robots.

Dr Tim Helps, lead author and developer of the LAZA system said: “With the LAZA, we apply electrostatic forces directly on the wing, rather than through a complex, inefficient transmission system. This leads to better performance, simpler design, and will unlock a new class of low-cost, lightweight flapping micro-air vehicles for future applications, like autonomous inspection of off-shore wind turbines.”

Professor Rossiter added: “Making smaller and better performing flapping wing micro robots is a huge challenge. LAZA is an important step toward autonomous flying robots that could be as small as insects and perform environmentally critical tasks such as plant pollination and exciting emerging roles such as finding people in collapsed buildings.”

• PAPER – Liquid-amplified zipping actuators for micro-air vehicles with transmission-free flapping. T. Helps, C. Romero, M. Taghavi, A. Conn and J. Rossiter. Science Robotics, vol. 7 (63)

Torrey Smith, Co-Founder of Endiatx, is changing the reputation endoscopies have for being uncomfortable. At Endiatx, they are developing a pill-sized robot that you swallow, which will then livestream your digestive system for a doctor to view. Our interviewer Abate dives in.

Torrey Smith
Torrey Smith is the Co-Founder & CEO of Endiatx, a medical robotics company that manufactures tiny robotic pills capable of active movement inside the human stomach with control over internet protocol. Prior to launching Endiatx, he developed medical devices in the areas of endometrial ablation, atherectomy, therapeutic hypothermia, sleep apnea, and vascular closure.

An aerospace engineer by training, he takes a keen interest in the deep tech sector and is a proud mentor of up-and-coming founders at the Founder Institute. He is also the principal founder of the international arts collective known as Sextant, and he has had his art featured in the Smithsonian.

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AI-designed (C-shaped) organisms push loose stem cells (white) into piles as they move through their environment. Credit: Douglas Blackiston and Sam Kriegman

By Joshua Brown, University of Vermont Communications

To persist, life must reproduce. Over billions of years, organisms have evolved many ways of replicating, from budding plants to sexual animals to invading viruses.

Now scientists at the University of Vermont, Tufts University, and the Wyss Institute for Biologically Inspired Engineering at Harvard University have discovered an entirely new form of biological reproduction—and applied their discovery to create the first-ever, self-replicating living robots.

The same team that built the first living robots (“Xenobots,” assembled from frog cells—reported in 2020) has discovered that these computer-designed and hand-assembled organisms can swim out into their tiny dish, find single cells, gather hundreds of them together, and assemble “baby” Xenobots inside their Pac-Man-shaped “mouth”—that, a few days later, become new Xenobots that look and move just like themselves.

And then these new Xenobots can go out, find cells, and build copies of themselves. Again and again.

“With the right design—they will spontaneously self-replicate,” says Joshua Bongard, Ph.D., a computer scientist and robotics expert at the University of Vermont who co-led the new research.

The results of the new research were published in the Proceedings of the National Academy of Sciences.

Into the Unknown

In a Xenopus laevis frog, these embryonic cells would develop into skin. “They would be sitting on the outside of a tadpole, keeping out pathogens and redistributing mucus,” says Michael Levin, Ph.D., a professor of biology and director of the Allen Discovery Center at Tufts University and co-leader of the new research. “But we’re putting them into a novel context. We’re giving them a chance to reimagine their multicellularity.” Levin is also an Associate Faculty member at the Wyss Institute.

As Pac-man-shaped Xenobot “parents” move around their environment, they collect loose stem cells in their “mouths” that, over time, aggregate to create “offspring” Xenobots that develop to look just like their creators. Credit: Doug Blackiston and Sam Kriegman

And what they imagine is something far different than skin. “People have thought for quite a long time that we’ve worked out all the ways that life can reproduce or replicate. But this is something that’s never been observed before,” says co-author Douglas Blackiston, Ph.D., the senior scientist at Tufts University and the Wyss Institute who assembled the Xenobot “parents” and developed the biological portion of the new study.

“This is profound,” says Levin. “These cells have the genome of a frog, but, freed from becoming tadpoles, they use their collective intelligence, a plasticity, to do something astounding.” In earlier experiments, the scientists were amazed that Xenobots could be designed to achieve simple tasks. Now they are stunned that these biological objects—a computer-designed collection of cells—will spontaneously replicate. “We have the full, unaltered frog genome,” says Levin, “but it gave no hint that these cells can work together on this new task,” of gathering and then compressing separated cells into working self-copies.

“These are frog cells replicating in a way that is very different from how frogs do it. No animal or plant known to science replicates in this way,” says Sam Kriegman, Ph.D., the lead author on the new study, who completed his Ph.D. in Bongard’s lab at UVM and is now a post-doctoral researcher at Tuft’s Allen Center and Harvard University’s Wyss Institute for Biologically Inspired Engineering.

On its own, the Xenobot parent, made of some 3,000 cells, forms a sphere. “These can make children but then the system normally dies out after that. It’s very hard, actually, to get the system to keep reproducing,” says Kriegman. But with an artificial intelligence program working on the Deep Green supercomputer cluster at UVM’s Vermont Advanced Computing Core, an evolutionary algorithm was able to test billions of body shapes in simulation—triangles, squares, pyramids, starfish—to find ones that allowed the cells to be more effective at the motion-based “kinematic” replication reported in the new research.

“We asked the supercomputer at UVM to figure out how to adjust the shape of the initial parents, and the AI came up with some strange designs after months of chugging away, including one that resembled Pac-Man,” says Kriegman. “It’s very non-intuitive. It looks very simple, but it’s not something a human engineer would come up with. Why one tiny mouth? Why not five? We sent the results to Doug and he built these Pac-Man-shaped parent Xenobots. Then those parents built children, who built grandchildren, who built great-grandchildren, who built great-great-grandchildren.” In other words, the right design greatly extended the number of generations.

Kinematic replication is well-known at the level of molecules—but it has never been observed before at the scale of whole cells or organisms.

An AI-designed “parent” organism (C shape; red) beside stem cells that have been compressed into a ball (“offspring”; green). Credit: Douglas Blackiston and Sam Kriegman

“We’ve discovered that there is this previously unknown space within organisms, or living systems, and it’s a vast space,” says Bongard. “How do we then go about exploring that space? We found Xenobots that walk. We found Xenobots that swim. And now, in this study, we’ve found Xenobots that kinematically replicate. What else is out there?”

Or, as the scientists write in the Proceedings of the National Academy of Sciences study: “life harbors surprising behaviors just below the surface, waiting to be uncovered.”

Responding to Risk

Some people may find this exhilarating. Others may react with concern, or even terror, to the notion of a self-replicating biotechnology. For the team of scientists, the goal is deeper understanding.

“We are working to understand this property: replication. The world and technologies are rapidly changing. It’s important, for society as a whole, that we study and understand how this works,” says Bongard. These millimeter-sized living machines, entirely contained in a laboratory, easily extinguished, and vetted by federal, state and institutional ethics experts, “are not what keep me awake at night. What presents risk is the next pandemic; accelerating ecosystem damage from pollution; intensifying threats from climate change,” says UVM’s Bongard. “This is an ideal system in which to study self-replicating systems. We have a moral imperative to understand the conditions under which we can control it, direct it, douse it, exaggerate it.”

Bongard points to the COVID epidemic and the hunt for a vaccine. “The speed at which we can produce solutions matters deeply. If we can develop technologies, learning from Xenobots, where we can quickly tell the AI: ‘We need a biological tool that does X and Y and suppresses Z,’ —that could be very beneficial. Today, that takes an exceedingly long time.” The team aims to accelerate how quickly people can go from identifying a problem to generating solutions—”like deploying living machines to pull microplastics out of waterways or build new medicines,” Bongard says.

“We need to create technological solutions that grow at the same rate as the challenges we face,” Bongard says.

And the team sees promise in the research for advancements toward regenerative medicine. “If we knew how to tell collections of cells to do what we wanted them to do, ultimately, that’s regenerative medicine—that’s the solution to traumatic injury, birth defects, cancer, and aging,” says Levin. “All of these different problems are here because we don’t know how to predict and control what groups of cells are going to build. Xenobots are a new platform for teaching us.”

The scientists behind the Xenobots participated in a live panel discussion on December 1, 2021 to discuss the latest developments in their research. Credit: Wyss Institute at Harvard University

• PUBLICATION – Kinematic self-replication in reconfigurable organisms. Sam Kriegman, Douglas Blackiston, Michael Levin, and Josh Bongard, Proceedings of the National Academy of Sciences Dec 2021, 118 (49) e2112672118; DOI: 10.1073/pnas.2112672118

The new microbot inspired by starfish larva stirs up plastic beads. (Image: Cornel Dillinger/ETH Zurich)

By Rahel Künzler

Among scientists, there is great interest in tiny machines that are set to revolutionise medicine. These microrobots, often only a fraction of the diameter of a hair, are made to swim through the body to deliver medication to specific areas and perform the smallest surgical procedures.

The designs of these robots are often inspired by natural microorganisms such as bacteria or algae. Now, for the first time, a research group at ETH Zurich has developed a microrobot design inspired by starfish larva, which use ciliary bands on their surface to swim and feed. The ultrasound-​activated synthetic system mimics the natural arrangements of starfish ciliary bands and leverages nonlinear acoustics to replicate the larva’s motion and manipulation techniques.

Hairs to push liquid away or suck it in

Depending on whether it is swimming or feeding, the starfish larva generates different patterns of vortices. (Image: Prakash Lab, Stanford University)

At first glance, the microrobots bear only scant similarity to starfish larva. In its larval stage, a starfish has a lobed body that measures just a few millimetres across. Meanwhile, the microrobot is a rectangle and ten times smaller, only a quarter of a millimetre across. But the two do share one important feature: a series of fine, movable hairs on the surface, called cilia.

A starfish larva is blanketed with hundreds of thousands of these hairs. Arranged in rows, they beat back and forth in a coordinated fashion, creating eddies in the surrounding water. The relative orientation of two rows determines the end result: Inclining two bands of beating cilia toward each other creates a vortex with a thrust effect, propelling the larva. On the other hand, inclining two bands away from each other creates a vortex that draws liquid in, trapping particles on which the larva feeds.

Artificial swimmers beat faster

These cilia were the key design element for the new microrobot developed by ETH researchers led by Daniel Ahmed, who is a Professor of Acoustic Robotics for life sciences and healthcare. “In the beginning,” Ahmed said, “we simply wanted to test whether we could create vortices similar to those of the starfish larva with rows of cilia inclined toward or away from each other.

To this end, the researchers used photolithography to construct a microrobot with appropriately inclined ciliary bands. They then applied ultrasound waves from an external source to make the cilia oscillate. The synthetic versions beat back and forth more than ten thousand times per second – about a thousand times faster than those of a starfish larva. And as with the larva, these beating cilia can be used to generate a vortex with a suction effect at the front and a vortex with a thrust effect at the rear, the combined effect “rocketing” the robot forward.

Besides swimming, the new microrobot can collect particles and steer them in a predetermined direction. (Video: Cornel Dillinger/ETH Zurich)

In their lab, the researchers showed that the microrobots can swim in a straight line through liquid such as water. Adding tiny plastic beads to the water made it possible to visualize the vortices created by the microrobot. The result is astonishing: both starfish larva and microrobots generate virtually identical flow patterns.

Next, the researchers arranged the ciliary bands so that a suction vortex was positioned next to a thrust vortex, imitating the feeding technique used by starfish larva. This arrangement enabled the robots to collect particles and send them out in a predetermined direction.

Ultrasound offers many advantages

Ahmed is convinced that this new type of microrobot will be ready for use in medicine in the foreseeable future. This is because a system that relies only on ultrasound offers decisive advantages: ultrasound waves are already widely used in imaging, penetrate deep inside the body, and pose no health risks.

“Our vision is to use ultrasound for propulsion, imaging and drug delivery.”

– Daniel Ahmed

The fact that this therapy requires only an ultrasound device makes it cheap, he adds, and hence suitable for use in both developed and developing countries.

Ahmed believes one initial field of application could be the treatment of gastric tumours. Uptake of conventional drugs by diffusion is inefficient, but having microrobots transport a drug specifically to the site of a stomach tumour and then deliver it there might make the drug’s uptake into tumour cells more efficient and reduce side effects.

Sharper images thanks to contrast agents

But before this vision can be realized, a major challenge remains to be overcome: imaging. Steering the tiny machines to the right place requires that a sharp image be generated in real time. The researchers have plans to make the microrobots more visible by incorporating contrast agents such as those already used in medical imaging with ultrasound.

In addition to medical applications, Ahmed anticipates this starfish-​inspired design to have important implications for the manipulation of smallest liquid volumes in research and in industry. Bands of beating cilia could execute tasks such as mixing, pumping and particle trapping.

• PAPER – Ultrasound-​activated ciliary bands for microrobotic systems inspired by starfish. Dillinger C, Nama N and Ahmed D. Nat Commun. 2021 Nov 9. doi: 10.1038/s41467-​021-26607-ycall_made

This articled was originally published at the official website of ETH Zürich. Read the original article here.

DNA origami is a technique that allows scientists to create 3D bots made from DNA. Image credit – Daniele Adami, licensed under CC BY 2.0

By Anthony King

Doctors know that we need smarter medicines to target the bad guys only. One hope is that tiny robots on the scale of a billionth of a metre can come to the rescue, delivering drugs directly to rogue cancer cells. To make these nanorobots, researchers in Europe are turning to the basic building blocks of life – DNA.

Today robots come in all shapes and sizes. One of the strongest industrial robots can lift cars weighing over two tons. But materials such as silicon are not so suitable at the smallest scales.

While you can make really small patterns in solid silicon, you can’t really make it into mechanical devices below 100 nanometres, says Professor Kurt Gothelf, chemist and DNA nanotechnologist at Aarhus University in Denmark. That’s where DNA comes in. ‘The diameter of the DNA helix is only two nanometres,’ says Prof. Gothelf. A red blood cell is about 6,000 nanometres across.

Lego

Dr Tania Patiño, a nanotechnologist at the University of Rome in Italy, says DNA is like Lego. ‘You have these tiny building blocks and you can put them together to create any shape you want,’ she explained. To continue the analogy, DNA comes in four different coloured blocks and two of the colours pair up opposite one another. This makes them predictable.

Once you string a line of DNA blocks together, another line will pair up opposite. Scientists have learnt how to string DNA together in such a way that they introduce splits and bends. ‘By clever design, you branch out DNA strands so that you now have three dimensions,’ said Prof Gothelf. ‘It is very easy to predict how it folds.’

Dr Patiño is developing self-propelled DNA nanorobotics in her project, DNA-Bots. ‘DNA is highly tuneable,’ she said. ‘We can have software that shows us which sequences produce which shape. This is not possible with other materials at this tiny scale.’

While DNA nanorobots are a long way from being used in people, with Prof. Gothelf saying that ‘we won’t see any medicines based on this in the next ten years,’ progress is being made in the lab. Already scientists can obtain a string of DNA from a virus, and then design using software shorter stretches of DNA to pair with and bend the string into a desired shape. ‘This amazing technique is called DNA origami,’ said Prof. Gothelf. It allows scientists to create 3D bots made from DNA.

In an early breakthrough, Prof. Gothelf’s research lab made a DNA box with a lid that opened. Later, another group built a barrel-shaped robot that could open when it recognised cancer proteins, and release antibody fragments. This strategy is being pursued so that one day a DNA robot might approach a tumour, bind to it and release its killer cargo.

‘With nanorobots we could have more specific delivery to a tumour,’ said Dr Patiño. ‘We don’t want our drugs to be delivered to the whole body.’ She is in the lab of Professor Francesco Ricci, which works on DNA devices for the detection of antibodies and delivery of drugs.

Meanwhile, the network Prof. Gothelf heads up, DNA-Robotics, is training young scientists to make parts for DNA robotics that can perform certain actions. Prof. Gothelf is working on a ‘bolt and cable’ that resembles a handbrake on a bike, where force in one place makes a change in another part of the DNA robot. A critical idea in the network is to ‘plug and play,’ meaning that any parts built will be compatible in a future robot.

This has the potential to make a completely new generation of drugs.

Prof. Kurt Gothelf, Aarhus University, Denmark

Bloodstream

As well as carrying out specific functions, most robots can move. DNA robots are too miniscule to swim against our bloodstream, but it is still possible to engineer into them useful little engines using enzymes.

Dr Patiño previously developed a DNA nanoswitch that could sense the acidity of its environment. Her DNA device also worked as a self-propelling micromotor thanks to an enzyme that reacted with common urease molecules found in our bodies and acted as a power source. ‘The chemical reaction can produce sufficient energy to generate movement,’ said Dr Patiño.

Movement is important to get nanorobots to where they need to be. ‘We could inject these robots in the bladder and they harvest the chemical energy using urease and move,’ said Dr Patiño. In future such movement ‘will help them to treat a tumour or a disease site with more efficiency that passive nanoparticles, which cannot move.’ Recently, Patiño and others reported that nanoparticles fitted with nanomotors spread out more evenly than immobile particles when injected into the bladder of mice.

Rather than swim through blood, nanobots might be able to pass through barriers in our body. Most problems delivering drugs are due to these biological barriers, such as mucosal layers, notes Dr Patiño. The barriers are there to impede germs, but often block drugs. Dr Patiño’s self-propelled DNA robots might change these barriers’ permeability or simply motor on through them.

Stability

Nanoparticles can be expelled from a patient’s bladder, but this option isn’t as easy elsewhere in the body, where biodegradable robots that self-destruct might be necessary. DNA is an ideal material, as it is easily broken down inside of us. But this can also be a downside, as the body might quickly chew up a DNA bot before it gets the job done. Scientists are working on coating or camouflaging DNA and strengthening chemical bonds to boost stability.

One other potential downside is that naked pieces of DNA can be viewed by the immune system as signs of bacterial or viral foes. This may trigger an inflammatory reaction. As yet, no DNA nanobot has ever been injected into a person. Nonetheless, Prof. Gothelf is confident that scientists can get around these problems.

Indeed, stability and immune reaction were obstacles that the developers of mRNA vaccines – which deliver genetic instructions into the body inside a nanoparticle – had to get over. ‘The Moderna and the Pfizer (BioNTech) vaccines (for Covid-19) have a modified oligonucleotide strand that is formulated in a nano-vesicle, so it is close to being a small nanorobot,’ said Prof. Gothelf. He foresees a future where DNA nanorobots deliver drugs to exactly where needed. For example, a drug could be attached to a DNA robot with a special linker that gets cut by an enzyme that is only found inside certain cells, thus ensuring that drug is set free at a precise location.

But DNA robotics is not just for nanomedicine. Prof. Gothelf is mixing organic chemistry with DNA nanobots to transmit light along a wire that is just one molecule in width. This could further miniaturise electronics. DNA bots could assist manufacturing at the smallest scales, because they can place molecules at mind bogglingly tiny but precise distances from one another.

For now though, DNA robotics for medicine is what most scientists dream about. ‘You could make structures that are much more intelligent and much more specific than what is possible today,’ said Prof. Gothelf. ‘This has the potential to make a completely new generation of drugs.’

The research in this article was funded by the EU. If you liked this article, please consider sharing it on social media.

This post Foldable, organic and easily broken down: Why DNA is the material of choice for nanorobots was originally published on Horizon: the EU Research & Innovation magazine | European Commission.

The laser steering device is able to trace complex trajectories such as an exposed wire as well as a word within geometrical shapes. Credit: Wyss Institute at Harvard University

A microrobotic opto-electro-mechanical device able to steer a laser beam with high speed and a large range of motion could enhance the possibilities of minimally invasive surgeries

By Benjamin Boettner

Minimally invasive surgeries in which surgeons gain access to internal tissues through natural orifices or small external excisions are common practice in medicine. They are performed for problems as diverse as delivering stents through catheters, treating abdominal complications, and performing transnasal operations at the skull base in patients with neurological conditions.

The ends of devices for such surgeries are highly flexible (or “articulated”) to enable the visualization and specific manipulation of the surgical site in the target tissue. In the case of energy-delivering devices that allow surgeons to cut or dry (desiccate) tissues, and stop internal bleeds (coagulate) deep inside the body, a heat-generating energy source is added to the end of the device. However, presently available energy sources delivered via a fiber or electrode, such as radio frequency currents, have to be brought close to the target site, which limits surgical precision and can cause unwanted burns in adjacent tissue sections and smoke development.

Laser technology, which already is widely used in a number of external surgeries, such as those performed in the eye or skin, would be an attractive solution. For internal surgeries, the laser beam needs to be precisely steered, positioned and quickly repositioned at the distal end of an endoscope, which cannot be accomplished with the currently available relatively bulky technology.

Responding to an unmet need for a robotic surgical device that is flexible enough to access hard to reach areas of the G.I. tract while causing minimal peripheral tissue damage, Researchers at the Wyss Institute and Harvard SEAS have developed a laser steering device that has the potential to improve surgical outcomes for patients. Credit: Wyss Institute at Harvard University

Now, robotic engineers led by Wyss Associate Faculty member Robert Wood, Ph.D., and postdoctoral fellow Peter York, Ph.D., at Harvard University’s Wyss Institute for Biologically Inspired Engineering and John A. Paulson School for Engineering and Applied Science (SEAS) have developed a laser-steering microrobot in a miniaturized 6×16 millimeter package that operates with high speed and precision, and can be integrated with existing endoscopic tools. Their approach, reported in Science Robotics, could help significantly enhance the capabilities of numerous minimally invasive surgeries.

This collage shows a prototype of the laser steering device creating a star trajectory at 5000 mm/s. Credit: Wyss Institute at Harvard University

In this multi-disciplinary approach, we managed to harness our ability to rapidly prototype complex microrobotic mechanisms…provide clinicians with a non-disruptive solution that could allow them to advance the possibilities of minimally invasive surgeries in the human body with life-altering or potentially life-saving impact.

Robert Wood

“To enable minimally invasive laser surgery inside the body, we devised a microrobotic approach that allows us to precisely direct a laser beam at small target sites in complex patterns within an anatomical area of interest,” said York, the first and corresponding author on the study and a postdoctoral fellow on Wood’s microrobotics team. “With its large range of articulation, minimal footprint, and fast and precise action, this laser-steering end-effector has great potential to enhance surgical capabilities simply by being added to existing endoscopic devices in a plug-and-play fashion.”

The team needed to overcome the basic challenges in design, actuation, and microfabrication of the optical steering mechanism that enables tight control over the laser beam after it has exited from an optical fiber. These challenges, along with the need for speed and precision, were exacerbated by the size constraints – the entire mechanism had to be housed in a cylindrical structure with roughly the diameter of a drinking straw to be useful for endoscopic procedures.

“We found that for steering and re-directing the laser beam, a configuration of three small mirrors that can rapidly rotate with respect to one another in a small ‘galvanometer’ design provided a sweet spot for our miniaturization effort,” said second author Rut Peña, a mechanical engineer with micro-manufacturing expertise in Wood’s group. “To get there, we leveraged methods from our microfabrication arsenal in which modular components are laminated step-wise onto a superstructure on the millimeter scale – a highly effective fabrication process when it comes to iterating on designs quickly in search of an optimum, and delivering a robust strategy for mass-manufacturing a successful product.”

The microrobotic laser-steering end-effector (on the right) can be used as a fitted add-on accessory for existing endoscopic systems (on the left) for use in minimally invasive surgery. Credit: Wyss Institute at Harvard University

The team demonstrated that their laser-steering end-effector, miniaturized to a cylinder measuring merely 6 mm in diameter and 16 mm in length, was able to map out and follow complex trajectories in which multiple laser ablations could be performed with high speed, over a large range, and be repeated with high accuracy.

To further show that the device, when attached to the end of a common colonoscope, could be applied to a life-like endoscopic task, York and Peña, advised by Wyss Clinical Fellow Daniel Kent, M.D., successfully simulated the resection of polyps by navigating their device via tele-operation in a benchtop phantom tissue made of rubber. Kent also is a resident physician in general surgery at the Beth Israel Deaconess Medical Center.

“In this multi-disciplinary approach, we managed to harness our ability to rapidly prototype complex microrobotic mechanisms that we have developed over the past decade to provide clinicians with a non-disruptive solution that could allow them to advance the possibilities of minimally invasive surgeries in the human body with life-altering or potentially life-saving impact,” said senior author Wood, Ph.D., who also is the Charles River Professor of Engineering and Applied Sciences at SEAS.

The laser steering device performing a colonoscope demo in a life-size model of the colon. Credit: Wyss Institute at Harvard University

Wood’s microrobotics team together with technology translation experts at the Wyss Institute have patented their approach and are now further de-risking their medical technology (MedTech) as an add-on for surgical endoscopes.

“The Wyss Institute’s focus on microrobotic devices and this new laser-steering device developed by Robert Wood’s team working across disciplines with clinicians and experts in translation will hopefully revolutionize how minimally invasive surgical procedures are carried out in a number of disease areas,” said Wyss Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital, and Professor of Bioengineering at SEAS.

The study was funded by the National Science Foundation under award #CMMI-1830291, and the Wyss Institute for Biologically Inspired Engineering.

• PUBLICATION – Microrobotic laser steering for minimally invasive surgery Peter A. York, Rut Peña, Daniel Kent and Robert J. Wood. Science Robotics, 6(50).

Interesting discussion with Prof. Ali Khademhosseini, CEO of the Terasaki Institute, and one of the pioneers of the Bioengineering field. Prof. Ali’s journey from Harvard and UCLA to the Terasaki Institute is truly inspiring. What does the institute do to bring a product to the real world? Learn about the design challenges of biomaterials, organs on a chip, and soft robotics in this episode of the IEEE RAS Soft Robotics Podcast.

You can also listen to this podcast on Spotify and Apple Podcasts, and explore support options on Patreon.

Interesting discussion with Hod Lipson, head of Creative Machines Lab, Columbia University in New York. Can robots be self-aware? Can they design other robots and self-repair? Why should we evolve robots to do tasks that animals do so well? Why don’t we have useful autonomous robots in the real world yet? Find out Hod’s answers to these questions and updates on VoxCAD development for designing and simulation of soft robots in this episode of the IEEE RAS Soft Robotics Podcast.

What’s more, Hod gave his personal advice to roboticists being interviewed for an assistant professorship and to 1st-year robotics PhD students looking for a thesis topic, and he also commented on his approach to the ethical dilemma of military funding scientific research. I hope you enjoy listening to the episode! You can check Hod Lipson’s portfolio here: https://www.hodlipson.com/

You can also listen to this podcast on Spotify and Apple Podcasts, and explore support options on Patreon.

In this episode, Audrow Nash interviews Eric Diller, Assistant Professor at the University of Toronto, on wireless micro-scale robots that could eventually be used in human surgery.  Diller speaks about the design, control, and manufacture of micro-scale surgical robotic devices, as well as when we might see this technology in the operating room.

Eric Diller

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In this episode, Abate interviews David Mindell, co-founder of Humatics. David discusses a system they developed that can detect the location of a special tracking device down to a centimeter level accuracy. They are currently developing a device to detect location down to a millimeter level accuracy. This solves a the core problem of localization for robots. David discusses the technology behind these products and their applications.

David Mindell

David co-founded Humatics with a mission to revolutionize how people and machines locate, navigate and collaborate. He is a professor of Aeronautics and Astronautics at MIT, as well as the Dibner Professor of the History of Engineering and Manufacturing, and Chair of the MIT Task Force on the Work of the Future. He has participated in more than 25 oceanographic expeditions and is an inventor on 8 patents in autonomous helicopters, AI-assisted piloting, and RF navigation. He is the author of five books, including Our Robots, Ourselves:Robotics and the Myths of Autonomy (2015) and Digital Apollo: Human and Machine in Spaceflight (2008). David has undergraduate degrees from Yale and a Ph.D. from MIT.

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In this episode, Marwa ElDiwiny interview Peer Fisher, a Professor of Physical Chemistry at the University of Stuttgart and the Director of the Micro Nano and Molecular Systems Lab at the Max Planck Institute for Intelligent Systems.  Fischer discusses micro robots that has been designed to move inside of environments similar to the human body called, “micro swimmers.”  He talks about how they are fabricated, powered, and how they can move with light or “nano propellers.”  Fischer also discusses simulating human tissue and the future of micro and nano robots, including how they could be a replacement for certain surgeries.

Peer Fischer

Peer Fischer is a Professor of Physical Chemistry at the University of Stuttgart and he heads the independent Micro Nano and Molecular Systems Lab at the Max Planck Institute for Intelligent Systems in Stuttgart.

He received a BSc. degree in Physics from Imperial College London and a Ph.D. from the University of Cambridge. He was a NATO (DAAD) Postdoctoral Fellow at Cornell University, before joining the Rowland Institute at Harvard. At Harvard he held a Rowland Fellowship and directed an interdisciplinary research lab for five years. In 2009 he received an Attract Award from the Fraunhofer Society which led him to set up a photonics lab at the Fraunhofer Institute for Physical Measurement Techniques in Freiburg. In 2011 he moved his lab to the Max Planck Institute for Intelligent Systems in Stuttgart, and since 2013 he is a Professor at the University of Stuttgart.

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In this episode, Jack Rasiel interviews Vijay Kumar, Professor and Dean of Engineering at the University of Pennsylvania.  Kumar discusses the guiding ideas behind his research on micro unmanned aerial vehicles, gives his thoughts on the future of robotics in the lab and field, and speaks about setting realistic expectations for robotics technology.

Vijay Kumar

Vijay Kumar is the Nemirovsky Family Dean of Penn Engineering with appointments in the Departments of Mechanical Engineering and Applied Mechanics, Computer and Information Science, and Electrical and Systems Engineering at the University of Pennsylvania.

Dr. Kumar received his Bachelor of Technology degree from the Indian Institute of Technology, Kanpur and his Ph.D. from The Ohio State University in 1987. He has been on the Faculty in the Department of Mechanical Engineering and Applied Mechanics with a secondary appointment in the Department of Computer and Information Science at the University of Pennsylvania since 1987. In his time at the university, Dr. Kumar has held numerous positions including director of the GRASP Laboratory, Chairman of the Department of Mechanical Engineering and Applied Mechanics, and Deputy Dean for Education in the School of Engineering and Applied Science. From 2012 to 2013, he served as the assistant director of robotics and cyber physical systems at the White House Office of Science and Technology Policy.

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Fabrication and complete assembly of a Geneva drive device using the iMEMS method. The left panel shows the layer-by-layer fabrication of support structures and assembly of gear components. The image on the right shows the complete device after the layers have been sealed. Image: SauYin Chin, Columbia Engineering.

A team of researchers led by Biomedical Engineering Professor Sam Sia at Columbia Engineering has developed a way to manufacture microscale machines from biomaterials that can safely be implanted in the body. Working with hydrogels, which are biocompatible materials that engineers have been studying for decades, Sia has invented a new technique that stacks the soft material in layers to make devices that have three-dimensional, freely moving parts. The study, published online January 4, 2017, in Science Robotics, demonstrates a fast manufacturing method Sia calls “implantable microelectromechanical systems” (iMEMS).

By exploiting the unique mechanical properties of hydrogels, the researchers developed a “locking mechanism” for precise actuation and movement of freely moving parts, which can function as valves, manifolds, rotors, pumps, and drug delivery systems. They were able to tune the biomaterials within a wide range of mechanical and diffusive properties and to control them after implantation without a sustained power supply, such as a toxic battery. They then tested the payload delivery in a bone cancer model and found that the triggering of releases of doxorubicin from the device over 10 days showed high treatment efficacy and low toxicity, at 1/10^th of the standard systemic chemotherapy dose.

“Overall, our iMEMS platform enables development of biocompatible implantable microdevices with a wide range of intricate moving components that can be wirelessly controlled on demand and solves issues of device powering and biocompatibility,” says Sia, also a member of the Data Science Institute. “We’re really excited about this because we’ve been able to connect the world of biomaterials with that of complex, elaborate medical devices.  Our platform has a large number of potential applications, including the drug delivery system demonstrated in our paper which is linked to providing tailored drug doses for precision medicine.”

Most current implantable microdevices have static components rather than moving parts and, because they require batteries or other toxic electronics, have limited biocompatibility. Sia’s team spent more than eight years working on how to solve this problem. “Hydrogels are difficult to work with, as they are soft and not compatible with traditional machining techniques,” says Sau Yin Chin, lead author of the study, who worked with Sia. “We have tuned the mechanical properties and carefully matched the stiffness of structures that come in contact with each other within the device. Gears that interlock have to be stiff in order to allow for force transmission and to withstand repeated actuation. Conversely, structures that form locking mechanisms have to be soft and flexible to allow for the gears to slip by them during actuation, while at the same time they have to be stiff enough to hold the gears in place when the device is not actuated. We also studied the diffusive properties of the hydrogels to ensure that the loaded drugs do not easily diffuse through the hydrogel layers.”

The team used light to polymerize sheets of gel and incorporated a stepper mechanization to control the z-axis and pattern the sheets layer by layer, giving them three-dimensionality. Controlling the z-axis enabled the researchers to create composite structures within one layer of the hydrogel while managing the thickness of each layer throughout the fabrication process. They were able to stack multiple layers that are precisely aligned and, because they could polymerize a layer at a time, one right after the other, the complex structure was built in under 30 minutes.

Sia’s iMEMS technique addresses several fundamental considerations in building biocompatible microdevices, micromachines, and microrobots: how to power small robotic devices without using toxic batteries; how to make small biocompatible moveable components that are not silicon, which has limited biocompatibility; and how to communicate wirelessly once implanted (radio frequency microelectronics require power, are relatively large, and are not biocompatible). The researchers were able to trigger the iMEMS device to release additional payloads over days to weeks after implantation. They were also able to achieve precise actuation by using magnetic forces to induce gear movements that, in turn, bend structural beams made of hydrogels with highly tunable properties. (Magnetic iron particles are commonly used and are FDA-approved for human use as contrast agents.)

In collaboration with Francis Lee, an orthopedic surgeon at Columbia University Medical Center at the time of the study, the team tested the drug delivery system on mice with bone cancer. The iMEMS system delivered chemotherapy adjacent to the cancer, and limited tumor growth while showing less toxicity than chemotherapy administered throughout the body.

“These microscale components can be used for microelectromechanical systems, for larger devices ranging from drug delivery to catheters to cardiac pacemakers, and soft robotics,” notes Sia. “People are already making replacement tissues and now we can make small implantable devices, sensors, or robots that we can talk to wirelessly. Our iMEMS system could bring the field a step closer to developing soft miniaturized robots that can safely interact with humans and other living systems.”

The study, “Additive manufacturing of hydrogel-based materials for next-generation implantable medical devices,” was supported by an NSF CAREER award, NIH R01 grant (HL095477-05), and NSF ECCS-1509748. Chin was supported by the National Science Scholarship (PhD) awarded by the Agency for Science, Technology and Research (Singapore). The researchers have a patent pending.

If you enjoyed this article, you may also enjoy:

• The rise of China’s medical robotics sector
• Robots at your service: Empowering healthy aging at European Robotics Week, 2016
• Considering robot care, ethics & future tech at #ERW2016 European Robotics Week
• Survey: Evaluate ethics of health related privacy with care robots
• Care-O-bot 4 celebrates its premiere as a shopping assistant
• Robot companions are coming into our homes — how human should they be?

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Image: Festo

Ask a child to design a robot, and they’ll produce a drawing that looks a little like you or I—the parts may be gray and boxy, but it will have two arms, two legs, and a head (probably with an antenna coming out of the top). Starting from the beginning of robotics, the human form has seemed like an excellent starting point. One of the best places to draw inspiration for robotic design, however, is the kingdom of insects, arachnids, snails, and slugs.

Challenges inherent in the human form

Here’s a simple question: how do you walk? It’s not by putting one foot in front of another. You walk by falling, and then catching yourself. This is a really complex movement, which has been best described by mathematical models that describe the human body as an inverted pendulum. Therefore, it’s safe to say that walking upright is not an easy challenge for robots to master. A recent DARPA robotics challenge—showcasing the most advanced humanoid robots on Earth—still saw nearly half of the contestants fall flat on their faces.

Designing robots to imitate humans—or any mammal—is a huge challenge. Our gait, our musculature, even the ways we see the world are all vastly more complicated than any machine we’ve ever made. Insects are simpler creatures by contrast, and therefore are much easier to replicate.

The insectoid advantage

Here are a few reasons why a budding robot designer should study insects. First of all, insects get a lot of mobility out of small bodies with simple joints. Better still, they’re robust—a ladybug can fly into a window, bounce off, and keep going. Small, mobile, and durable—all of these qualities represent admirable characteristics in a practical robot.

Small robots can be produced easily en masse, which can also lend itself to useful applications. By mimicking the swarming behavior of a cockroach, the makers of a robot known as Velociroach hope to use their tiny robots as rescue workers. Small robots can easily crawl through the cracks and crevices of a collapsed building in order to locate survivors and notify rescue workers.

Similarly, small insect bodies equate to small insect brains. While this isn’t likely to be much help to an insect in an IQ test, it’s a great way for engineers to study the secrets of robot autonomy. Despite their small brains, insects can avoid predators and display complex behavior. Even a creature as simple as a maggot—with just 10,000 neurons—can still learn relatively complex tasks, and can actually be trained to a certain extent.

The metamorphosis from insects to robots

Insects are simple enough that a myriad of insect-inspired robots have already made it from the drawing board into real life. Researchers from Seoul University have made a robot, for example, that takes its cues from the water strider—it can literally jump on water.  Sensors based on light-sensing organs found in insects have been used to stabilize drones.  Other robots have demonstrated the ability to swarm like ants.

When designing a robot, it makes sense to copy simpler organisms first, and then move on to more complex organisms. Robotics engineers have already learned a great deal from insects, and this knowledge lends itself to advancements in both mechanics and artificial intelligence.

If you enjoyed this bio-inspired article, you might also be interested in:

• QuadBot: The 3D printed crab-bot scuttling beyond its Kickstarter goal
• Robohub roundtable: Robotic bee swarms from Black Mirror – what’s hype, what’s real?
• New insect-inspired vision strategy could hasten development of mini-drones
• A drone with insect-inspired folding wings
• mROBerTO: The modular millirobot for swarm behavior studies

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

In this roundtable edition, we watched the Black Mirror episode “Hated in the Nation” and asked our Robohub team members: with many institutions focused on developing aerial drone technology, and in light of the pressing reality of climate change and bee colony collapse, do we see robotic bees in our future? Would swarms of artificial insects even be desirable?

In her book “The Ultimate Quotable Einstein”, Alice Calaprice asserted that Einstein probably never said anything close to: “If the bee disappeared off the surface of the globe then man would only have four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man.”

Still. Whoever said it, it’s a haunting prophecy. With climate change thought to be forcing colony collapse disorder and threatening the existence of many pollinators, might swarm robotics hold the key to humanity’s survival? Could these robot bees ever be hacked to spy and become weaponised? In our roundtable we discussed the technology in the Black Mirror episode “Hate the Nation” and some of the pitfalls.

Swarms of autonomous, 3D printed drone bees pollinating the nation. Hackable AI, vulnerable to attack. Flying tools turned aerial enemy. Do our experts think any of this could happen? Is this type of technology likely or even feasible?

Our team share their thoughts:

Sabine: What’s interesting is that not everything in the episode is entirely crazy. We do want to create technology that addresses a specific need. If there are fewer pollinators, we might want to create artificial pollinators, though not necessarily artificial bees, to help us along the path to addressing the issue. But I think the technology in Black Mirror is very far from something we can do today.

There was a project called RoboBees, that was Harvard-based, that was all about creating artificial bees for pollination—so exactly this scenario.  There were multiple parts and problems: how do you make very small flyers; how do you drive them in a controlled way; and how do they sustain enough energy. All these things are extremely hard to address. They’ve managed to make some of the world’s best miniature flyers that can flap their wings and take off, and are making some great steps in controlling them. But when I say control, I really mean turning left and right in a laboratory setting. If you were to put them outside in a windy environments, it’d be a completely different story, and they don’t really have the energy to go very far.

And then there’s the algorithms. It’s not just the bees in this episode, they’re all connected to hives and they have all these control algorithms implemented that allow them to find flowers and people with image processing. How do you get such large numbers of drones to communicate with each other and their hubs? There are multiple communication issues that are very hard to address. What is interesting is that [Black Mirror] put together these bees with the swarm approach, and the pollinate in a way that’s very bio-inspired.

Kassie: Does anyone think that this episode did a disservice to swarm robotics in that someone was able to hack into the mainframe and essentially attack and kill people? That’s a very real fear that people have with regards to robotics and AI.

Sabine: For years we had to answer the question: Have you read “Prey”? Is this likely to happen? And now it’s: Have you seen “Dark Mirror”?

Ioannis: In fairness, there is some justification for this, as opposed to questions about terminators and things.

Sabine: And it’s not the technology [in Black Mirror] that’s the problem, it’s the humans. The technology starts by being portrayed as a real positive. All the tech in this episode, like the autonomous cars, is actually really cool and helpful. It’s the people who screwed up, ultimately, and the system got hacked. So I think the key message is that we need to make the technology secure.

Ioannis: Did you think it was a little short-sighted in the way it portrayed swarm robotics? It sounds very inefficient to me to have a central control that’s required to monitor the flight of every bee. All the bad guy needed to do was hack the central control to manipulate every bee. A swarm is something different than a million drones. In the episode, it looks like a swarm, but in reality it’s actually a lot of remotely operated robots.

Sabine: That’s right. And if it was properly decentralised, it would have been harder to hack because you wouldn’t be downloading massive amounts of code on every one of these bees.

Ioannis: To make the swarm go from controlled to bad, the hacker could have introduced some kind of memory or code to enable the swarm to evolve rapidly, and from that point on it’s out of control. That would have been interesting. Instead, the hacker just uses the bees as lots of tele-operated robots. I found the episode a little disappointing in this aspect.

Kassie: If you’re doubting robotics in any way, this episode is perhaps something you could look at and think: “Oh my God, this is something that could happen.” But I took some positives from this [with robotics] then only negatives.

Sabine: I felt the autonomous cars were positive; similar to what you’d expect them to be like in 30 years or so.

Ioannis: They portray autonomous cars as being cool, also, which is one aspect. But the fact that the cars are autonomous is nothing [to the story], the characters just use them, which I think is quite cool actually. They ignore the fact that these could be anything futuristic which I think is good.

Kassie: It was almost a precursor to something that could actually happen soon, in that some people were still driving, but the people with money had autonomous systems. And it wasn’t portrayed as scary! So I agree that that was a good aspect.

Sabine: I think the point of Black Mirror is very often not the technology but that people misuse it, and they make a very good point about online bullying [in this episode].

Ioannis: Yes, and they do not portray online bullies in a stereotypical way. For example, there is a teacher character who is a very nice lady in reality, but online is something completely different. Sabine, I’d like to ask you what you think about the potential of a weaponized swarm for defense purposes?

Sabine: I think it’s a very bad idea to weaponize swarms. You have to think about such things as stability and payload, accounting for wind and conditions etc. How would you do that? And why use a swarm as opposed to another type of robot with another type of payload?

Ioannis: I don’t have any specific examples for swarm robotics, but in nature a lion is dangerous, and so is a mosquito. Both in different way. So there could be an application.

Sabine: In that sense, you can weaponize anything. It’s just so much harder to weaponize a swarm than a more capable system, at least today.

Ioannis: What did you think of the robo-bee design?

Sabine: I think it was pretty cool, but too complex. If you were to design a robo-bee you would design something like a mini-copter that would sit on a plant, rather than something that looked like a bee. Or you might have an agriculture robot that simply goes across fields and does the pollination. Although the nice thing about the bee design is that the infrastructure is still already in place—plants etc.

If you enjoyed this article, you may also want to read our other Roundtables:

• Robohub roundtable: Public perceptions of robotics and AI, what’s your pet peeve?
• Robohub roundtable: Why do robotics crowdfunding projects fail?
• Robohub roundtable: Cybathlon and advancements in prosthetics
• Robohub roundtable: Job loss through automation, Foxconn controversy
• Robohub roundtable: Why is it so difficult to define ‘robot’?

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Developed by a team at the University of Toronto, mROBerTO (milli-ROBot TORonto) is designed for swarm-robotics researchers who might wish to test their collective-behavior algorithms with real physical robots. With just a 16 mm x 16 mm footprint, mROBerTO can be used in a multitude of other miniature robot projects too—its modular design allowing for easy addition or removal of components.

mROBerTOs can determine any nearby robots’ relative distances and bearings by their unique robot IDs (up to 150 mm sensing radius) with the use of modulated IR signals. To achieve this, mROBerTO has an all-around coverage of IR phototransistors and emitters that can receive and send modulated IR signals. Furthermore, mROBerTO is equipped with Bluetooth Smart and ANT Wireless communication capabilities, which allow point-to-point and mesh network communication among robots. As for movement, there are two small motors located at the back of the robot that act as wheels and move the robot in a differential-drive configuration.

mROBerTO modular components. Image: University of Toronto

The majority of swarm robotics research has so far been limited to running virtual simulations for the purpose gathering experimental data. In order to test swarm behavior algorithms in a more realistic setting, we have to use physical robots in an environment where real-world constraints act upon the experiments. However, a swarm will often consist of tens—even hundreds—of robots operating together. So robots should ideally be as small as possible if these swarm algorithms are to be tested in a lab setting with limited work-space. And since we need a large number of these robots for experiments, we should aim to use only off-the-shelf components for easy assembly, production, and maintenance. In addition, certain swarm algorithms may require special sensing capabilities in the swarm robots, requiring modular in-design to allow quick exchanges of processing and sensing hardware. mROBerTO was designed to address these specific issues.

At the moment, there are no commercially available mROBerTOs. The BoM costs approximately 60 USD, and the source files of both the hardware and software can be provided by the developers. mROBerTOs were developed using the Eclipse IDE with SEGGER J-Link programmer/debugger but any integrated development environment that supports ARM GCC can be used to develop on mROBerTOs. For wireless debugging and development purposes, we recommend the user getting an nRF51 or nRF52 development board to wirelessly communicate with mROBerTOs.

mROBerTO was developed by Goldie Nejat, Justin Y. Kim, Tyler Colaco, Zendai Kashino and Beno Benhabib at the University of Toronto, Department of Mechanical Engineering. The latest version of the robot was completed in June 2016 and first featured in 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) as ‘mROBerTO: A Modular Millirobot for Swarm-Behavior Studies’.

If you liked this article, you may also want to read these other articles on swarm robotics:

• Swarms of precision agriculture robots could help put food on the table
• Machines can learn by simply observing, without being told what to look for
• Raffaello D’Andrea at TED2016: Novel flying machines and swarms of tiny flying robots
• Scaling up underwater swarmbot research from tabletop ‘aquarium’ to the Venice Lagoon (CoCoRo Video #50/52)

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Most of D’Andrea’s work shown at this latest demonstration is dedicated to pushing the boundary of what can be achieved with autonomous flight. One key ingredient is localization: To function autonomously, robots need to know where they are in space. Previously his team has relied on an external high-precision motion capture system available in his Flying Machine Arena at ETH Zurich for positioning. In his previous TED talk on robot athletes for example, you can clearly see the reflective markers required by the motion capture system. This meant that most algorithms were difficult to demonstrate outside the lab. It also meant that the system had a single point of failure (SPOF) in the centralized server of the mocap system — a highly problematic point for any safety critical system.

In another world first, Raff and his team are now showing a newly developed, doubly redundant localization technology from Verity Studios, a spin-off from his lab, which gives flying machines, and robots in general, new levels of autonomy. For the live demonstrations, all flying machines use on-board sensors to determine where they are in space and on-board computation to determine what their actions should be. There are no external cameras. The only remote commands the flying robots receive are high level ones, such as “take-off” or “land”.

The nature of this performance was also unprecedented in that it did not use safety nets to separate the audience from the action, and in that it even saw dozens of vehicles fly directly above the audience.

The performance included demonstrations of various safety systems for flying machines, including a large, high-performance quadcopter that is fully redundant and that utilizes a state-of-the-art failsafe algorithm (see previous Robohub article) among its many other onboard and offboard safety features.

Following extensive technical discussions on the various failure modes of the positioning system and of each flying machine as well as on the systems’ numerous redundancies and safety features, the organizers of TED had full faith in the systems’ safety and reliability. So much so that they decided to indemnify the venue against any lawsuits to overcome its ban on drones.

Here is the video:

And here is a more in-depth breakdown of what you are seeing, based on a transcript of the presentation and information from Raff D’Andrea’s team:

Intro video – Institute for Dynamic Systems and Control (IDSC), ETH Zurich

The video shows some of the previous work of D’Andrea’s group on aerial construction: A 6-meter tall tower built out of 1500 foam bricks by four autonomous quadcopters over a three day period in front of a live audience and a rope bridge built by three autonomous quadcopters in the Flying Machine Arena.

Live demo 1: Tail-Sitter – IDSC, ETH Zurich

The Tail-sitter. Photo: Bret Hartman / TED

“This is a so-called tail-sitter. It’s an aircraft that tries to have its cake and eat it: Like other fixed wing aircraft, it is efficient in forward flight, much more so than helicopters and variations thereof. Unlike most other fixed wing aircraft, however, it can hover, which has huge advantages for take-off, landing, and general versatility. There is no free lunch, unfortunately, and one of the challenges with this type of aircraft is its susceptibility to disturbances, such as wind-gusts, while hovering. We are developing control architectures and algorithms that address this limitation. [Pushes the vehicle, then grabs it and throws it] The idea is to allow the aircraft to autonomously recover no matter what situation it finds itself in. [Second throw] And through practice, improve its performance over time. [Third throw, violently spinning the vehicle]”

Demo 2 (video of demo the night before): Monospinner – IDSC, ETH Zurich

The Monospinner. Photo: Marla Aufmuth / TED

“When doing research we often ask ourselves abstract, fundamental questions that try to get at the heart of a matter. One such question: What is the minimum number of moving parts necessary for controlled flight? This line of exploration may have practical ramifications; take helicopters, for example, which are affectionately known as “machines with over 1000 moving parts all conspiring to cause bodily harm”. Turns out that decades ago skilled pilots were flying RC airplanes with only 2 moving parts: a propeller and a tail rudder. We recently discovered that it could be done with only 1.”

“This is the monospinner, the world’s mechanically simplest, controllable flying machine, invented just a few months ago. It has only one moving part, a propeller. There are no flaps or hinges, no control surfaces or valves, no other actuators. Just one propeller. Even though it is mechanically simple, there is a lot going on in its electronic brain to keep it stable and move through space in a controllable fashion. Even so, it does not yet have the recovery algorithms of the tail-sitter, which is why I have to throw it just right.”

Live demo 3: Omnicopter – IDSC, ETH Zurich:

The Omnicopter. Photo: Bret Hartman / TED

“If the monospinner is an exercise in frugality, this machine here, the omnicopter, with its 8 propellers, is an exercise in excess. What can you do with this surplus? The thing to notice is that it is highly symmetric, and as a result it is ambivalent to orientation. This gives it an unprecedented capability: It can move anywhere in space, independently of where it is facing, and even of how it is rotating. It has its own complexities, mainly due to the complex, interacting flows of its 8 propellers. Some of this can be modeled, while the rest can be learned on the fly. [Omnicopter takes off, manoeuvres around the stage, lands]”

Live demo 4: Fully redundant multicopter – Verity Studios

Fully redundant quadcopter. Photo: Ryan Lash / TED

“If flying machines are going to find their way into our daily lives, they will need to become extremely safe. This machine here is a prototype being developed by Verity Studios. It actually consists of two separate, two propeller flying machines, each capable of controlled flight. One wants to rotate clockwise, the other one counter clockwise. When all systems are operational, it behaves like a high-performance, 4 propeller quadrocopter. [Quadcopter takes off and flies an arc across the stage] If anything fails, however – propeller, motor, electronics, even a battery pack – it is still able to fly, albeit in a degraded way [One half of the quad is de-activated, the quadrocopter starts to spin and fall, the failsafe mode kicks in and the quadrocopter recovers, flies to the back of the stage, and performs a controlled landing at the takeoff spot].”

Live demo 5: Synthetic swarm, 33 small flying machines – Verity Studios

Photo: Bret Hartman / TED

“This last demonstration is an exploration of synthetic swarms. The large number of coordinated autonomous entities offers a radically new palette for aesthetic expression. We have taken commercially available micro-quadrocopters, each weighing less than a slice of bread, and equipped them with our localization technology and custom algorithms. Because each unit knows where it is in space and is self-controlled, there really is no limit to their number. [Swarm performance]”

Raffaello D’Andrea wrapped up with: “Hopefully these demonstrations will motivate you to dream up new revolutionary roles for flying machines. For example, the ultra-safe flying machine [points to the fully redundant multicopter] has aspirations to become a flying lampshade on Broadway. The reality is that it is difficult to predict the impact of nascent technology. And for folks like us, the real reward is the journey, and act of creation. It is also a continual reminder of how wonderful and magical the universe we live in is; that it permits clever, creative creatures to sculpt it in such spectacular ways. The fact that this technology has huge commercial potential is just icing on the cake.”

More photos for your viewing pleasure:

Photo: Bret Hartman / Ryan Lash / TED

Photo: Bret Hartman / Ryan Lash / TED

Photo: Bret Hartman / Ryan Lash / TED

Photo: Steven Rosenbaum / Waywire

Transcript below.

In this episode, Audrow Nash speaks with Brad Nelson, Professor at ETH Zurich, about his research regarding micro and nano robotics. They discuss many of Nelson’s projects: retinal and heart surgery, crystal harvesting, and robots with simulated flagella for mobility.

The video below shows some of the research discussed during the interview.

Brad Nelson 

Brad Nelson has been the Professor of Robotics and Intelligent Systems at ETH Zürich since 2002, where his research focuses on microrobotics and nanorobotics. Fundamentally, he is interested in how to make tiny intelligent machines that are millimeters to nanometers in size.

He studied mechanical engineering at the University of Illinois and the University of Minnesota, worked as a computer vision researcher at Honeywell and a software engineer at Motorola, served as a United States Peace Corps Volunteer in Botswana, Africa, and then obtained a Ph.D. in Robotics from Carnegie Mellon University. He was an Assistant Professor at the University of Illinois at Chicago and an Associate Professor at the University of Minnesota before moving to ETH.

Links:

• Download mp3 (18.4 MB)
• Subscribe to Robots using iTunes
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• Link to the Muli-Scale Robotics Lab

Transcript

Audrow Nash: Hi, can you introduce yourself?

Brad Nelson: My name is Brad Nelson. I am a professor of robotics and intelligence systems at ETH Zurich. I’ve been there for almost 13 years now.

Audrow Nash: Can you give me the big picture goal of your research?

Brad Nelson: The focus of our research is micro and nano robotics. We’re trying to understand how to make machines as small as we can and, along the way, we develop fabrication techniques to manufacture them. We look at ways to make them move, we look at applications for them and try to put that all together. We try to move the technology from fundamental research into a spinoff, a clinical application or something we might license to another company.

Audrow Nash: Just how small are these machines?

Brad Nelson: We work on things that are millimeters down to nanometers in scale. One of the things we’ve worked on for several years now is a device we call an artificial bacterial flagella. It’s about the size of a bacteria, maybe 15 or 20 microns long. You could fit about three billion in a teaspoon. They’re very tiny, you put five of them head to head and they might be about the width of a hair.

These are the smallest things we can see with optical microscopes. But then we also do a lot of work on nano fabrication with nano wires and nano structures, where you can’t see them, even with optical microscopes, so we need electron microscopes. Some of these structures will go down to 30 nanometers in diameter. And then we have things we put in the eye that are perhaps a millimeter or two long.

Audrow Nash: What are some applications of those?

Brad Nelson: One thing we’ve been working on has been retinal surgery; ways we can deliver drugs to specific locations on the retina, to target diseases such as age related macular degeneration or diabetic retinopathy. We’ve also realized that some of the technologies are not just for moving micro robots, but can move small catheters and endoscopes that you might want to put into the body.

We also work on how we might guide, not just untethered autonomous machines but small endoscopes or catheters, into the heart or the brain.

Audrow Nash: Do you see applications outside of the medical field?

Brad Nelson: We do. Drug discovery is one. One of the methods for discovering drugs is to first develop models of proteins. In the human DNA, we know the atomic sequence of protein molecules but we still have to understand the structure.

In structural biology, one of the main methods used to determine the shape of these tiny little molecules is to isolate proteins and crystallize them – grow them into tiny crystals. We’ve developed some of our micro robotic technology to handle these tiny crystals and to automate the process of retrieving them from the “mother liquor” and place them on a loop. That device is then immediately freeze dried, with the protein crystal on it, and then put into a high-energy x-ray beam. The structural biologist can infer the shape from the x-ray diffraction pattern.

It’s a long process but nobody has been able to automate it, up to now, so we think we have a solution there.

Lately, we have also been thinking of ways we can use these devices to create a catalytic reaction to treat wastewater.

Audrow Nash: Catalytic reaction?

Brad Nelson: To photo catalyze pollutants, for instance, and take toxins that are in the environment and degrade them into harmless substances. The idea is to put micro robots into polluted water, to treat and clean it.

There are also sensing applications: we can put micro robots into an environment and look at what chemicals are there, what kinds of substances that we want to get rid of. So we can use them as sensors to monitor the environment.

Audrow Nash: To understand this a little bit better I would like to talk about a few of your projects. To begin with, controlling micro robots with five degrees of freedom, can you describe that?

Brad Nelson: One of the first challenges we have is how to make small things. There’s micro fabrication technology and we borrow from the semiconductor industry; to make small machines, it’s the same technology as for making computer chips.

The second problem is how to make these small machine move: what kind of technologies can you use? Is there some kind of chemical reaction? Can you use lasers to deliver energy? The community has kind of settled, recently, on the use of magnetic fields, so you generate fields externally with electromagnets.

Basically, you wrap a wire around some kind of an iron core and, as you generate the electric current around it, you can create weaker and stronger magnetic fields. By changing their strength, we can exert forces that work on these small devices if they’re made of magnetic material.

We first started doing this over a decade ago with just two degrees of freedom, making it move on a surface. Then we started working on three degrees, to make things move in the X to Y and Z coordinates and to rotate.

Then we turned to five degrees of freedom motion. We realized we were going to need several electromagnets for this. We did a lot of numerical simulations on a computer to understand where the best place to put these magnets was, and the best way to control them. We realized we needed at least eight electromagnets. We built a system we call the OctoMag, so that we can very precisely control the current in each magnet and move small things with it.

Audrow Nash: Why do you need eight electromagnets for five degrees of freedom?

Brad Nelson: That’s something that we never quite understood until just recently. One of my post docs is working with me on this. Looking at the math, he realized that we can actually prove mathematically that eight is the minimum. We knew people who built systems that only had six magnets and they were having issues.

Magnetic fields can generate a force or a torque on something. The torque is like a compass needle on a magnetic field; we always know it’s going to point to the north and align itself with the earth’s magnetic field. Just by taking our field and rotating it, we can get other things – the magnetic particles, structures and micro robots – to rotate too, to align with the field.

Forces are a little more complicated because they require a special gradient of the field. The field has to be getting stronger in a direction, so that the micro robot moves in that direction. It’s with this coupling that the math gets a little complicated; you see a dependency between how you generate the gradient and the magnetic field.

It means that, although with five degrees you might think you just need five electromagnets, you can’t generate obituary gradients and fields at the same time. You need to add more electromagnets, and the question is: what’s the minimum? For our problem, it happened to be eight. The theoretical results are about to appear online now. It’s fascinating. People have been trying to understand how fields are generated since the 1800s, the 1700s even, and we’re still discovering new things. I think that’s going to help spur us on to new ideas and ways of making small things move, which is really the ultimate goal of what we’re trying to do.

Audrow Nash: This technology has gone into your startups. In addition to using small robots for crystallography, can you talk a bit about having a viable business model in research for this? Did you begin the research with a plan to market it?

Brad Nelson: I became a professor in 1995, so 20 years ago. My goal then was just to do interesting research, write good, grand proposals to get funding and to publish papers that people wanted to read. I think we’ve been successful in that.

Then, along the way, we started to get interested in getting our technologies out into the real world and that is a tremendous challenge. It’s one thing to have a research result to publish and another to actually develop a technology that people want to pay money for and use, and to help improve peoples’ lives in some way.

As I’ve developed my research agenda over the past 20 years, I started to think more carefully about potential business plans that might make sense. In biomedical, it’s clear you need to have patents and to be aware of what the patent landscape is. Even now, with some of our Masters projects, we will often go and just look at what patents are out there in this area.

If somebody like Siemens or Phillips already has a patent in an area, it can block the technology. It doesn’t make sense to go down a route where somebody has the IP locked up and, even if you do develop the new technology, there’s no chance of getting it out. You start to think in terms of: can you own, or do you have the potential to own, some important intellectual property in the area and develop it. You also consider, as you’re working on things, what potential therapies might this benefit and does it make sense, from a business standpoint, to develop these therapies.

Audrow Nash: What do you mean by therapies?

Brad Nelson: Well, for instance, one of our startups is called Aeon Scientific. They took our technology and they’re starting to look at some uses for magnetic fields. They looked at a lot of different areas and one thing they realized is that, with the aging population, more and more people need a particular heart procedure to treat a condition called Atrial Fibrillation, where your heart doesn’t beat properly; the electric signals don’t propagate through the heart.

Audrow Nash: It’s too fast or too slow or irregular?

Brad Nelson: Too fast or too slow or it doesn’t synchronize properly and so electrophysiologists and cardiac surgeons have discovered that, if they do a little therapy within the heart, they can reset it. People see potential to help a lot of people, but that also means potential to make money. It takes a tremendous investment to get this technology into the clinic. To justify that investment, you’ve got to realize a return on it. For that therapy, it makes sense.

Another therapy we’ve thought about is bronchoscopy, putting some of these devices into the lungs, particularly in premature infants, and trying to see which portion of their lung might be collapsed. That’s a therapy we’re interested in. The business model isn’t so convincing there; people just don’t project the potential number of cases that would justify the investment. That’s one of the reasons you’ve got funding agencies to enable you to progress further.

Audrow Nash: You mean funding agencies that fund research that’s not as in demand?

Brad Nelson: They fund research where the business model may not be clear. Although there are benefits, business investors may not find it persuasive, but it’s certainly going to be able to treat patients. We try to balance the two. We’re always trying to weigh up the problems we’re working on, the ones that have the potential to make a big impact. There are a lot of ways to measure this. One of these is the business case.

Audrow Nash: Going back to steerable catheter design with Aeon Scientific. So, you insert a catheter and that goes in through the arm or the groin or the neck, correct?

Brad Nelson: It goes through the femoral artery, near the groin. It enters the right chamber and then you can move over into the left chamber. You can get into all four chambers with this.

Audrow Nash: It has a flexible end that you direct using similar principles to the five degrees of freedom of manipulating small devices?

Brad Nelson: Yes, so the end of the catheter – the last few centimeters – is very floppy. At the very end is a permanent magnet. We can control its position and its orientation in the heart very precisely. We use that to deliver radio frequency therapy to ablate, to create this transmural ablation to stop electric signals from passing though certain areas of the heart.

Audrow Nash: The permanent magnet that’s at the end of the catheter is much bigger than some of the previous work you’ve done. Does the control of these magnetic robots scale?

Brad Nelson: It tends to scale well, although that needs a bit of explanation.

Generally, as devices get larger, magnetic fields can scale more favorably. But as they get smaller, it’s different. Magnetic forces and torques are a function of the volume of the magnet. Whenever you have something that depends on volume, as it gets smaller that’s not good, because if something is a cubic meter and then goes down to 10 centimeters, the size is decreased by just a factor of 10, but the volume has gone down by a factor of 1000. You’re getting these incredible decreases in the forces you can generate, so then we have to rethink our strategies. That’s where we’re inspired by nature – bacteria, for instance. We look at why E. coli swim with a rotary motor and use a flagella.

Audrow Nash: Describe the flagella a bit.

Brad Nelson: When Howard Berg [a professor of physics and molecular and cellular biology at Harvard] was in Colorado in 1973, he discovered that some bacteria, like E. coli and salmonella, have this little flagella. It’s a hair-like structure. People would look at it under a microscope and they couldn’t tell exactly how it moved. What Howard discovered, which surprised a lot of people, was that there was actually a rotary motor on this bacteria. People were astounded by that discovery. It was the first example of rotational motion in nature.

Audrow Nash: So it moves forwards in a similar way as a screw into wood?

Brad Nelson: Yeah, it’s like a screw, so it rotates this hair, this flagella, into a kind of helix shape, like a coil, and it propels itself that way. There’s a lot of physics, a lot of biology about why this works so well at these scales, that’s fascinating. How did nature evolve this kind of a structure? That’s a wonderful question.

We looked at it and realized that we can’t build that motor. It’s about 45 nanometers in diameter and it’s got 30 or 40 parts that are made out of proteins. What we could make, using some recent developments in nanotechnology, is these tiny little screws. Then we realized, if we put little magnets on the screws and rotated that field, we could get them to turn just like the E. coli flagella do. So they started propelling themselves, moving in fluid. That was in about 2007. We were surprised how well it worked and, as we understood the physics and the mathematics in the fabrication issues behind it, it’s been a very thrilling, rewarding area of research.

We’re always discovering something new and we’ve recently published a couple of papers. In one of them we’ve put DNA on these structures and we’ve demonstrated that, as we swim them near cells, we can get the cells to take up the DNA and then do gene transfection and express these.

The DNA would be coded for a particular florescent protein, so then the cells would express it and we can watch the cells start to light up. It demonstrates that we can target individual cells and do gene transfection with them.

In another project we’ve taken 80,000 of these ABF – the Artificial Bacteria of Flagella. We took this huge swam and injected it into the peritoneal cavity of a mouse and we’ve tracked it swimming within it. That paper’s recently come out.

Audrow Nash: What applications are there in that?

Brad Nelson: What we’re trying to do is demonstrate how we could potentially load some kind of drug on to these, and then target a particular location in the body. We demonstrated that we can load DNA and do transfection, then we demonstrated that we can move swarms of them and target particular locations, in this case in a mouse. Then, eventually, the furthest steps would be putting some kind of a drug that may treat a condition on there, and trying to target some very specific location, maybe a tumor in the body, and getting them to swarm around it and deliver the drug in a very localized area.

Audrow Nash: What do you think is the future and timeline of micro and nano robots?

Brad Nelson: I really think the field has made tremendous strides in the past 10 to 15 years. There are so many interesting problems and so many results that surprise me. I certainly think that within the next decade we’ll see these devices in clinical trials.

If we’re looking at medical applications, the first people we have to get interested in this are the doctors, the people who are really going to use it. They have to understand what the potential is and they have to understand what conditions could be treated with it. They have to get excited about it and be willing to work with us on it.

The first thing is you get doctors involved. Doctors have spent some of their valuable time with us on this. It takes tremendous investment and resources to get these things pushed through, to get all the engineering done properly and the FDA regulations, or whatever medical regulations need to be followed. That means you need business people; you need investment, so you need to convince business people too.

You’ve got to bring together, not just the engineers and scientists, but also the medical doctors and the business side. That’s what always makes it difficult to predict exactly how long this will take. With the right resources we can move very quickly, but not everybody’s vision is in alliance, initially. I certainly hope and expect that within less than a decade we’ll see applications in the clinics. I think, with this kind of thing, once it gets going, more and more things – things we can’t see right now – will start to emerge. I’m very confident about that.

Audrow Nash: Thank you.

Brad Nelson: Thank you very much.

All audio interviews are transcribed and edited for clarity with great care, however, we cannot assume responsibility for their accuracy.

If you like this post you may also enjoy:

• Micro-robotics and medicine: Interview with Toshio Fukuda
• Minimally-invasive eye surgery on the horizon as magnetically-guided microbots approach clinical trials
• Better micro-actuators to transport materials in liquids
• Crowdsourcing new strategies for cancer treatment: Towards swarming nanobots
• Robots Podcast: Nanosystems

Transcript below.

In this interview, Audrow Nash talks to two teams from Mobile Microrobotics Challenge at the 2015 International Conference for Robotics and Automation (ICRA).

The first team was from the University of Hawaii, Manoa. We spoke with Leanne King about the Autonomous Mobility & Accuracy Challenge. In this competition, teams try to move a small robot accurately around a shape. The robot can be a small piece of metal or even a bubble generated by a laser. Leanne’s team won the Mobility & Accuracy Challenge.

The second team was from West University of Timișoara (UVT) in Romania. We spoke to Ioan Alexandru Ivan about the Microassembly Challenge, where teams tried to move small triangles against walls and other fixtures using a micro-robot. The Ivan’s team placed second in the Microassembly Challenge.

Links:

• Download mp3 (8.9 MB)
• Subscribe to Robots using iTunes
• Subscribe to Robots using RSS
• ICRA 2015 Mobile Microrobotics Challenge

Transcript:

Microrobotics Mobility and Accuracy Challenge: Interview 1

Audrow Nash:  I’m at ICRA at the …

Edward Nerad:  … Mobile Microrobotics Challenge.

Audrow Nash:  And I am speaking to a team from …

Leanne King:  … University of Hawaii, Manoa.

Audrow Nash:  Would you introduce yourself?

Leanne King:  My name is Leanne, I’m a senior Electrical Engineering student at Manoa. I’m joined by Edward and Caralyn. Edward just graduated and Caralyn is also is a senior.

Audrow Nash:  Would you tell me a bit about the Challenge, the Mobility Challenge?

Leanne King:  The Mobility Challenge was where you had to autonomously traverse three different shapes: a rectangle a triangle and a circle as quickly and accurately as possible. Teams were judged based on time, how big a robot you had and accuracy; how many landmarks you hit on the field.

Audrow Nash:  First, what are these robots?

Leanne King:  Microrobotics could be anything really. Most teams use magnetic dust and electromagnetics to control it. Our team uses bubbles. We generate our bubbles using lasers.

Audrow Nash:  You generate the bubble using a laser?

Leanne King:  Yes.

Audrow Nash:  How does that work?

Leanne King: When you heat oil to a certain point, it creates differences in the surface tension. The thermal changes create surface tension in certain areas at the laser point that then generates a bubble.

Audrow Nash:  Differences in surface tension?

Leanne King:  Yeah, so then we can control that bubble using the same principle. The bubble wants to go to the laser.

Audrow Nash: Changing the surface tension of the area around it moves the bubble?

Leanne King:  Yes.

Audrow Nash:  Interesting. And so you direct the laser around these shapes and that’s how you control where the bubble goes for these challenges?

Leanne King:  Yes, we pick certain points, like critical points. For example, a triangle has three vertices, we pick those three points and then the computer finds a solution for those lines and the laser just steps through them.

Audrow Nash: Is there a vision system? How are you looking at what this bubble does?

Leanne King:  We have a camera looking thorough a microscope objective lens and that’s really it. We connected it to a computer and that’s how you see …

Audrow Nash:  And you select the points manually, where you want it to go?

Leanne King:  Yes, we pick our points. We were working on a visual system, using a camera, but it’s a little less reliable because our fields get dirty. So we decided to do it manually.

Audrow Nash:  What are some of the major challenges with this?

Leanne King:  Of our personal major challenges, our laser strength is very critical. If we don’t have a strong enough laser, or enough of a focused laser, the bubble won’t generate or we won’t be able to move it efficiently. The scale of the competition, because it’s on a micro scale …

Audrow Nash:  Can you relate the scale to something?

Leanne King:  Hair.

Audrow Nash:  Like, is it 100^th of the thickness of a hair?

Leanne King:  It’s like the thickness of a hair.

Audrow Nash:  The thickness of a hair.

Leanne King:  Yeah, the robots can be no bigger than 500 micrometers, and fields, I think, are three centimeters long. The entire course is 3 centimeters. It’s pretty small.

Audrow Nash:  What are some future applications of this kind of research?

Leanne King:  We’ve been doing some research into what this can be used for. Right now this is kind of a proof of concept thing that we can do something so small and move objects around with other small objects. Some research is already being done in the medical field where you can move particles in packets of medicine through a body with micro-robots. That will give us better precision and quicker recovery time or healing processes, and things like that. It has a lot of medical applications so far.

Audrow Nash:  Are there applications outside of the medical field?

Leanne King:  If you were able to create a system that can be put onto, for example, the BP oil spill, it can move those micro-particles and clean up the spill without humans needing to be in the water. If you move the micro-particles quickly, it will be able to clean it a little bit more efficiently.

Audrow Nash:  How do you feel about the competition so far?

Leanne King:  We’re enjoying it, we’re enjoying ourselves. Yesterday we did very well in the autonomous portion of the contest; we were one of only two teams to complete the challenge. That secures us first or second place, depending on how well we did compared to the other team. Today, we had some problems moving triangles in the mobility challenge, but we know what happened, what went wrong and how to fix it. So we’ll be back next year.

Audrow Nash:  Thank you.

Leanne King:  No, thank you.

Microrobotics Assembly Challenge: Interview 2

Audrow Nash: Would you tell me who you are?

Ioan Alexandru Ivan: I’m Alex Ioan, I’m an assistant professor at the University of Timișoara, which is located next to the capital city of Bucharest, Romania.

Audrow Nash: Would you tell me a bit about the Microassembly Challenge?

Ioan Alexandru Ivan: The Microassembly Challenge consists of pushing very small triangular objects, roughly the size of a human hair, into a very narrow channel of less than a millimeter in diameter. To be precise, it’s 750 microns, 0.75 of a millimeter. The winning team is the one that can insert the most triangular objects into this channel in two minutes.

There are several actuation principles involved, namely electromagnetics – these microrobotic devices are not tethered. This means that you cannot wire them; they should be operated wirelessly.

Audrow Nash: Yes, and so you control them with magnetic forces?

Ioan Alexandru Ivan: Yeah, with magnetic forces.

Audrow Nash: Can you tell me a bit about your setup that uses magnetic forces?

Ioan Alexandru Ivan: We use a set of four coils as you can see here. We have an arena, in the middle region, and inside we have the microrobotic agent that is a neodymium micro magnet of around 220 micrometers, each side.

Audrow Nash: What I’m looking at is a series of… there are four coils here?

Ioan Alexandru Ivan: Yeah.

Audrow Nash: And the coils, their cylinders in the top part are facing the neodymium magnet, correct? That’s in the center of all four coils, it kind of looks like a plus sign.

Ioan Alexandru Ivan: Well, we will generate magnetic gradient and this will attract the neodymium orient and the neodymium magnet towards the magnetic gradient field. So, with a joystick, we are able to drive these four coils and have very smooth movement.

Audrow Nash:  What does the neodymium magnet do?

Ioan Alexandru Ivan:  The neodymium magnet is the magnetic agent. It will respond to the magnetic field generated by the coils.

Audrow Nash:  So, the neodymium magnet – is that what you’re moving?

Ioan Alexandru Ivan:  Yes.

Audrow Nash:  The coils that are in the plus shape, you put a current through them and this generates a magnetic field that moves the neodymium magnet – that’s the small microrobot that you’re moving. And it’s moving on a X-Y plane.

Ioan Alexandru Ivan:  Exactly, X-Y and rotation.

Audrow Nash:  And rotation.

Ioan Alexandru Ivan:  And rotation: X-Y-R. They’re also doing 5D [indicating another group] so they also do Z, they have a much more complex setup.

Audrow Nash:  So one of the groups behind us does depth as well.

Ioan Alexandru Ivan:  Yeah, definitely you should ask them questions. However, we focused on integration, as you can see we have an all-inclusive device, all integrated.

Audrow Nash:  Yes, it’s very small.

Ioan Alexandru Ivan:  We have the smallest of the most compact ones and it’s very low cost. It’s based on open source technology. Here, you can see the Raspberry Pi …

Audrow Nash:  So you have a Raspberry Pi with a touch screen?

Ioan Alexandru Ivan:  Yeah, we developed a sort of shield for this one. We would like, eventually, to advertise it on Kickstarter or something like that.

Audrow Nash:  That would be cool.

Ioan Alexandru Ivan:  So we intend to further develop this product. It can help a lot for teaching, for instance. You can teach actuation principles, you can teach image processing, you can teach control systems.

Audrow Nash: It’s a nice little package for it.

Ioan Alexandru Ivan: Yes.

Audrow Nash: I agree. So, going back to the competition, you’re moving this neodymium magnet and it is pushing around these little triangles to try to put them together or put them against the wall. How did the competition go?

Ioan Alexandru Ivan: Quite well. Many competing teams were able to insert triangles and we also managed several. Right now, we’re having a small issue with one of the rules because they …

Audrow Nash: If the triangles go on to the borders.

Ioan Alexandru Ivan:  If it goes out of bounds. In bounds, the ruling is a little bit fuzzy.

Audrow Nash:  It’s not clear, I see.

Ioan Alexandru Ivan:  But we still managed to insert around five or six triangles in the two- minute window.

Audrow Nash:  And so, what are some of the applications of this technology?

Ioan Alexandru Ivan:  Well, the main application could be biomedical. For instance, this type of task simulates pushing objects or medicine, drugs, into blood vessels or noninvasive surgery. One day, robotic agents with some cancer treatment drugs will be driven through the body to the tumor, and they will locally deliver chemo static medicines. I think this field will really grow; microrobotics develops more and more as the technology advances towards nanotechnology, micro-technology. This has huge potential for the future.

Audrow Nash:  What about microassembly, actually building very small robots or something else, does this technology encompass that as well?

Ioan Alexandru Ivan: Yeah, you can build things.

Audrow Nash:  What can we do with these small things?

Ioan Alexandru Ivan: We could build 3D micro systems, 3D MEMS (Micro-Electro-Mechanical Systems), besides the medical applications. Presently, MEMS are based on planar technology but, in the future, for further integration, some parts of the MEMS could be assembled in 3D to build, for instance, more integrated actuators, more lab-on-a-chip integrated devices that are not possible today. This could also be a way forward for more integrated applications.

Audrow Nash:  Would this be similar to how they are now layering transistors for more space, rather than just moving along one plane?

Ioan Alexandru Ivan:  Yeah, I’m not entirely familiar with that technology.

Audrow Nash:  But that doesn’t require microrobots.

Ioan Alexandru Ivan:  Well, I don’t know. Probably one day we’ll have extremely small devices based on this technology. They could be, for instance, taken by microrobotic manipulators and placed inside very small systems. The idea is to embed intelligence but we’re quite far from that stage.

Audrow Nash:  Well, not actually intelligence within the robot but in how you control it, with an external magnetic field or a laser for example, correct?

Ioan Alexandru Ivan:  Yeah, for the moment we cannot embed intelligence in a tiny robot under a millimeter. But these incremental steps will help, in the future, to develop such systems. It’s groundwork for future applications. The more we integrate, the more we are able to manipulate accurately and this will allow us to make the next generation of robots more integrated and more intelligent.

Audrow Nash:  Thank you.

“Auklet flock Shumagins 1986” by D. Dibenski -Wikimedia

Imagine a swarm of microscopic robots that we inject into the vascular system: the swarm swims to the source of the problem, then either delivers therapeutics or undertakes microsurgery directly.

That was how I opened a short invited talk at the Royal Society of Medicine on 5 February, at a meeting themed The Future of Robotics in Surgery. The talk was a wonderful opportunity for me to introduce swarm intelligence and speculate on the likelihood of surgical micro-robot swarms, while at the same time learning about robot surgery. Here are the slides from my talk (with links to YouTube videos where available).

The talk was in three parts.

First I introduced swarm intelligence, and its artificial counterpart swarm robotics. I showed, with examples from two of my students, how – with very simple rules – a swarm of robots can keep together as a swarm, while moving toward a beacon. Then, with a phagocyte-like behaviour, encapsulate the beacon. In our case these were lab robots moving toward an infra-red beacon, but it’s not hard to imagine the same behavioural rules in a microscopic swarm swimming toward the source of a chemical marker (chemotaxis). I then gave two examples of the state of the art in swarm robotics: SYMBRION and (my current favourite) TERMES. I wanted to illustrate emergent physical interaction, in these two cases swarm self-assembly and swarm construction, respectively.

In part two I outlined what is by far the biggest problem: actually engineering robots at the micro-scale. Here I drew upon the examples from my book Robotics: a very short introduction; a section called A swarm of medical microrobots.  Start with cm sized robots. These already exist in the form of pillbots and I reference the work of Paolo Dario’s lab in this direction. Then get 10 times smaller to mm sized robots. Here we’re at the limit of making robots with conventional mechatronics. The almost successful I-SWARM project prototyped remarkable robots measuring 4 x 4 x 3mm. But now shrink by another 3 orders of magnitude to microbots, measured in micrometers. This is how small robots would have to be in order to swim through and access (most of) the vascular system. Here we are far beyond conventional materials and electronics, but amazingly work is going on to control bacteria. In the example I give from the lab of Sylvain Martel, swarms of magnetotactic bacteria are steered by an external magnetic field and, interestingly, tracked in an MRI scanner.

In the final part of my talk I introduce the work of my colleague Sabine Hauert, on swarms of nanoparticles for cancer nanomedicine. These 5 – 500nm particles are controlled by changing their body size, material, coating and cargo so – in true swarm fashion – the way the nanoparticle swarm moves and interacts with much larger normal and tumour cells is an emergent property of the way the nanoparticles individually interact and cooperate. Sabine and her collaborators have created an online tool called NanoDoc, which allows anyone to edit the design of nanoparticles then run simulations to see how their designs perform. In this way the task of searching the huge design space is crowd-sourced. In parallel Sabine is also running mesoscale embodied simulations, using the Harvard Kilobots.

I concluded by suggesting that engineering micro or nanobots is not the only major challenge. At least as important are: (a) how would you program the swarm, and (b) how would such a swarm be approved for clinical use? But a deeply interesting question is the nature of the human-swarm interface. If a swarm of surgical microbots should become a practical proposition would we treat the swarm as a microscopic instrument under the surgeon’s control, or a smart drug that does surgery?

If you liked this article, you may also be interested in:

• Crowdsourcing new strategies for cancer treatment: Towards swarming nanobots
• Thousand-robot swarm self-assembles into arbitrary shapes
• Micro-robotics and medicine: Interview with Toshio Fukuda
• Minimally-invasive eye surgery on the horizon as magnetically-guided microbots move toward clinical trials
• Better micro-actuators to transport materials in liquids
• Micro bio-bots powered by beating heart cells
• Robots Podcast: Bacteria-propelled microrobots
• Swarmbots: James McLurkin on why, how, and when we will see swarm robotics in practice
• ShanghAI Lectures: Samia Nefti-Mezziani “Non-rational Particle Swarm Optimization”

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Illustration of the different micro-actuators that can be coated with active compounds. (Illustration: Peters C et al. Advanced Functional Materials 2014, reprinted with permission of Wiley.)

Researchers have developed improved forms of tiny magnetic actuators thanks to new materials and a microscopic 3D printing technology.

Scientists have been conducting research on micrometre-sized actuators that one day may make it possible to transport drugs or chemical sensor molecules to specific locations throughout the human body. Researchers at ETH Zurich have now taken the development of such micro-devices a crucial step forward: a new production technology and new materials have made it possible to manufacture tiny actuators in any form and optimise them for future applications.

The elongated actuators elements, which can move through liquids, possess a helical shape and are magnetic. They are driven by an external rotating magnetic field; they align themselves along the magnetic field lines and rotate about their longitudinal axis. Due to their helical shape, they are able to swim forward through liquids.

When applying conventional fabrication techniques, the magnetic properties of these micro-objects depend on the shape of the devices themselves. This restriction made it difficult for researchers to develop  actuators with precise control and directional stability, as doctoral student Christian Peters from the group led by Christofer Hierold, Professor of Micro and Nanosystems, explains: “Previously, these elements wobbled as they moved forward, and they were less efficient because their magnetic properties were not ideal. We have now developed a material and a fabrication technique with which we can adjust the magnetic properties independent of the object’s geometry.”

Microscopic 3D printer

The scientists used a light-sensitive, bio-compatible epoxy resin, in which they incorporated magnetic nanoparticles. In the first part of the curing stage, they exposed a thin layer of this material to a magnetic field. This field magnetised the nanoparticles, leading to a particle re-arrangement in form of parallel lines. The orientation of these lines determines the magnetic properties of the material. The researchers then manufactured the tiny elongated structures out of the modified epoxy film via two-photon polymerisation. This technique is similar to a microscopic 3D printer: a laser beam is moved in a computer-controlled, three-dimensional manner within the epoxy resin layer, thus curing the resin locally. Uncured areas can then be washed away with a solvent.

This technique allowed the researchers to manufacture helical structures 60 micrometres in length and nine micrometres in diameter, and with a magnetisation perpendicular to the longitudinal axis. A conventional manufacturing method would not have allowed the production of an object with such magnetic properties, as the preferred magnetisation is usually in the direction of the longitudinal axis of an object, like a compass needle. The new actuators can be controlled precisely, they swim nearly four times as fast as previous elements, and they do not wobble.

New forms with larger surfaces

Previous micro-actuators usually took the shape of a corkscrew (helix), but thanks to the microscopic 3D fabrication technology the ETH scientists were able to produce modified shapes. In the study they fabricated structures similar to spiral-shaped, twisted strips and double-twisted wires. Tests show that these forms swim as fast as corkscrew-shaped actuators, but the new shapes differ from the latter in that their surface is two to four times larger. “This makes the actuators more interesting for certain applications,” says Salvador Pané, research associate in the group led by Bradley Nelson, Professor of Robotics and Intelligent Systems.

If such elements are to carry medications or chemical sensor molecules to specific locations in the body, the actuators must be coated with the corresponding molecules. And the larger the element’s surface, the larger the quantity of materials that can be transported. The researchers demonstrated that it is possible, in principle, to coat the structures with interesting biomedical materials by connecting antibodies to the surface of the spiral motors.

“But it is not just about swimming micro robots,” says Peters. “The new technology can also be used when other micro-objects have to be manufactured with specific magnetic properties.” The work is the result of many years of joint research between the two professors in the Department of Mechanical and Process Engineering in the fields of microsystems technology and micro-robotics, adds Pané. The group led by Nelson has many years’ experience in the fabrication and application of magnetic micro robots, and the group led by Hierold has a strong competence in the integration of new materials into microsystems.

This article originally appeared on ETH News. 

Literature reference

Peters C, Ergeneman O, Wendel García PD, Müller M, Pané S, Nelson BJ, Hierold C: Superparamagnetic Twist-Type Actuators with Shape-Independent Magnetic Properties and Surface Functionalization for Advanced Biomedical Applications. Advanced Functional Materials 2014. 24: 5269-5276, DOI:10.1002/adfm.201400596

If you liked this article, you may also be interested in:

• Video: Rise of the nanorobot, with Brad Nelson
• Minimally-invasive eye surgery on the horizon as magnetically-guided microbots move toward clinical trials
• Crowdsourcing new strategies for cancer treatment: Towards swarming nanobots
• Thousand-robot swarm self-assembles into arbitrary shapes

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Brad Nelson heads the Institute for Robotics and Intelligent Systems at ETH Zurich, where they focus on creating these nano devices inspired by the biological mechanisms of bacteria such as E. coli and salmonella.

Brad Nelson. Photo credit: ETH Zurich/Stéphanie Marie Couson

Brad Nelson is a Professor of Robotics and Intelligent Systems at ETH Zurich – The Swiss Federal Institute of Technology, Zurich. His primary research focus is on microrobotics and nanorobotics emphasizing applications in biology and medicine.

He has been the Department Head of Mechanical and Process Engineering at ETH, Chairman of the ETH Electron Microscopy Center, and is a member of the Research Council of the Swiss National Science Foundation. He is also a member of the board of directors for three Swiss companies.

More info:

Institute of Robotics and Intelligent Systems (IRIS)
Multi-Scale Robotics Lab (MSRL)
Brad Nelson’s Homepage
Brad Nelson’s TedX Talk

If you liked this article, you may also be interested in:

• Minimally-invasive eye surgery on the horizon as magnetically-guided microbots move toward clinical trials

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

When we imagine the future of warfare, we often envision a battlefield where humanoid robots and other machines fight alongside or in the place of human soldiers. From the droids of Star Wars to The Terminator’s cyborg soldiers, robots play a prominent role in our collective vision of future combat.

While science fiction is populated with anthropomorphic and sometimes malevolent robots that can seem remarkably human, in the real world, robots are simply programmable machines that can sense and interact with their environment. From this point of view, most advanced weapons systems are robotic, including cruise missiles, drones, and air and missile defense systems.

Are we at the beginning of an inevitable process leading to the rise of “killer robots” predicted by science fiction, or can robots actually make war less destructive?¹ What comes next in the advancement of military robots?

Developing Robotic Weapons

So far, autonomous robots have played a marginal role in warfare. Recently, however, the use of drones to counter the improvised explosive device (IED) threat in Iraq and carry out aerial bombing campaigns in Afghanistan, Pakistan, Yemen, and Somalia has elevated military robots to a more prominent role in U.S. military operations.^(a)

As the U.S. winds down its counterinsurgency campaigns in Iraq and Afghanistan, the most important robotic systems used in these conflicts will be far less in demand. These include IED hunters and unmanned aerial vehicles such as Northrop Grumman’s Global Hawk surveillance drones and General Atomics’ armed Predator and Reaper drones. In fact, the Department of Defense plans to slash these drones’ numbers due to both their inability to survive in contested airspaces and general budgetary pressures.

Instead, there will be a greater focus on developing robotic systems for shorter but more massive air campaigns against more sophisticated adversaries with modern air defense systems, like Libya, Syria, China, or Russia. The Pentagon will likely continue its efforts to build global precision strike capability, allowing rapid deployment of unmanned weapons that can attack anywhere in the world within an hour.^(b) In addition, there will be a continuing focus on technologies and capabilities relevant for low-intensity conflicts like the ongoing War on Terror.

As for the development of robot soldiers, despite decades of intensive research and continuous breakthroughs in robotics, the progress in creating autonomous military robots has been surprisingly slow. Several projects funded by the Defense Advanced Research Projects Agency (DARPA) have resulted in humanoid robot prototypes, but they lack the portable power source and intelligence that would allow them to act beyond very limited non-combat roles.

The most promising advancements have been the Navy’s X-47 drone, which recently mastered the art of landing on aircraft carriers, and humanoid robot prototypes such as DARPA’s rescue robot Atlas.^(c)

The Cyborgization of Human Soldiers

Another approach to implementing robotic weapons systems is to combine them with humans, whose bodies could be augmented with robotic technology. This concept offers the best of both worlds: the quick reaction times, precision, and strength of robotic systems and the control and superior cognitive abilities of humans.

DARPA’s Land Warrior and its successor projects (Objective Force Warrior, Future Force Warrior, and now Warrior Web) aim to equip soldiers with wearable computers, advanced communications gear, helmet visors with night vision and head-up-display, and robotic exoskeletons for improved mobility. While the potential may be vast, such human enhancement has suffered the same setbacks and slow progress as the development of other robotic systems. The gear is still too heavy, and the exoskeletons that could enable soldiers to carry more and move faster lack a sufficient power source.

At the same time, there has been remarkable progress in neuroscience with respect to mapping and manipulating the human brain.² Though not currently employed, a number of technologies have potential military applications. A technique called transcranial direct current stimulation (tDCS) has been shown to enhance the concentration and alertness of human test subjects.³ EEGs embedded in helmets might one day enable soldiers to control weapons through the power of thought. A research project at Duke University showed that a monkey with an implanted brain chip could control a robotic arm, and researchers at Brown University created the first wireless brain-computer interface in March.^(d)

The ultimate goal of some in the Pentagon is to develop “super soldiers” who could be deployed anywhere in the world within hours and remain in the field for extended periods of time. Their bodies and performance could potentially be enhanced through nanosensors that constantly monitor their medical status, embedded nanoneedles that release drugs when needed, and possibly even nanorobots that can quickly heal wounds in the field.^(e)

These “super soldiers” might be supported by a range of robotic devices and weapons systems, including robotic dogs to carry their gear, drones to resupply them, and robotic platforms from which to call in long-range precision strikes. The soldiers could one day assign robot helpers specific missions that they could then carry out with little human supervision.^(f)

Ethical Concerns And Scientific Unknowns

The use of military robots raises both ethical and tactical concerns. Will they be able to distinguish targets and use force proportionately? Will soldiers be willing to fight alongside completely autonomous robots? Could robots one day entirely replace humans and human-operated systems on the battlefield? What role might robots play in non-traditional wars such as the war on terror or the fight against transnational organized crime? These questions, along with other unknowns, have led United Nations Special Rapporteur Christof Heyns, Human Rights Watch, and other critics to call for a ban on autonomous military robots.⁴

Critics are also concerned that advanced artificial intelligence (AI) could develop in directions not anticipated by scientists. Because of this unpredictability, the US military has indicated that it will never remove humans from the decision loop completely. While unmanned weapons systems will become gradually more autonomous so that they can carry out very specific missions with less human direction, they may never entirely replace human soldiers on the battlefield.

The technological augmentation and modification of human soldiers raises even more troubling ethical issues than the development of autonomous robots.⁵ Since millions of dollars could go into technologically upgrading the body and mind of a single soldier, would the soldier be allowed to quit military service? What does it mean for an egalitarian and democratic society to provide certain individuals with superhuman abilities? While enhancing human soldiers may have its benefits, it opens up a web of ethical, political, and legal dilemmas.

What’s Next

Although truly autonomous military robots with strong artificial intelligence could potentially be built and deployed within the next twenty years, there are great doubts about their military usefulness and legality. Fully autonomous robots could easily turn out to be uncontrollable weapons. Furthermore, the difficult budgetary climate will not change in the foreseeable future, which means that the U.S. military has to focus its research and acquisition on the projects relevant to the most likely military needs. Instead of designing robots for war, the Pentagon may aim to enhance and even cyborgize soldiers while further developing human-operated robotic systems. Under the most likely scenarios, it may not be the Pentagon’s robots we should be worried about, but rather the changes in humans that military technology will inaugurate.

Welcome to Robohub, Toshio Fukuda. Can you tell us about your research?

In my lab at Nagoya University we do many different kinds of research: micro/nano robotic systems, medical robotics, and particularly medical simulators. We have many people working on medical robots and surgery robots right now. We are working on an intravascular robotic surgical system that could be used for brain surgery, for example, but one of our important areas is simulation-based medicine.

Let me explain simulation-based medicine … Before a medical doctor goes into surgery, he has to plan the surgery, and he used to have to do this in his own mind. But now he can use our simulator. For example, if you could practice an exam before taking it for real, you would be more likely to get a good score. Likewise, a medical doctor can use our simulator to rehearse his surgical plan so that when it is time for surgery, he can carry it out with confidence. This is especially important for intravascular surgery, where you have a team of doctors doing the surgery together.

Our simulator is not just for general purpose: we can create patient-specific models. We developed a system called EVE – it is short for EndoVascular Evaluator. It is for training, evaluation and simulation of endovascular surgery. We start by taking a CT scan of the patient and then we make physical model of the patient’s vascular system out of silicon using a 3D printing system. A fluid control unit is then used to simulate the patient’s circulation. Doctors can test their surgical plans on this simulator – it gives them the sensation of a real endovascular surgery.

I think this is the only such simulator available in the world so far. Of course there are virtual-reality-based simulators, and these can be good enough for a beginner, but there is a big difference between a virtual-reality-based simulator and a real physical simulator that can be used by a professional. It makes a big difference if a group of medical doctors can get together and make a plan in advance on how to carry out the surgery using a surgical model where they can see it and practice together on it … In a real situation, if you make a mistake, you have to stop what you are doing and sometimes you cannot carry out the surgery. This way a team of surgeons can make a careful plan in advance.

We have done this since 1998, and we have a built business from it since 2005… we have a company now called FAIN-Biomedical and are selling to the US, Italy, South Africa and also China, Korea and other places.

Can this system be used for training, too?

Of course you can use the simulator to train, but the big advantage is rehearsing just before surgery.

You have done micro-robotics for a long time. Can you tell us about that?

For intravascular surgery, you use a catheter; catheters are small wires about 1mm in diameter that can fit inside a patient’s brain veins. Also we are now expanding to the liver and to the heart, to do bypass surgery …

Your heart has 15 main blood vessels. These are very small and if one of them gets choked up, then you have a strain and the heart does not work properly. The doctor usually carries out bypass surgery, bypassing the choked up place to unblock the problem. That’s the conventional way. But with bypass surgery you have to open up the patient’s chest and then after that you have to close it up again and it takes a couple of weeks to recover from it. However in theory it’s just a catheter surgery that takes one or two hours and after that the patient can walk away from the hospital the same day or the next day. That’s what we call minimally invasive surgery or MIS and it’s becoming very popular because it doesn’t give much burden to the patient. Even after catheter surgeries in the brain or the heart the patient can walk away from the hospital the same day or next day.

The problem is that the doctor must have good skills to navigate the catheter, for example in brain surgery, from the thigh up to the brain where he uses a coil to remove the blockage. For this you need to be skilled, and if you make a mistake, there is no way to fix it.

I have been working with micro-robots for many, many years now. When I moved to Nagoya 25 years ago, a medical doctor came to me and looked at my micro-robots. At that time I had a small 7mm diameter micro-robot going inside of a tube, a kind of low-impact robot. This doctor looked at my robot and asked me if I could build a similar robot to be used for medical treatments in the blood vessels. But it’s not easy to make a 1mm- or 2mm-diameter robot that works inside a catheter. The head of the catheter can be shaped in such a way that it can make right or left turns, the same as steering functions. But there aren’t any commercial products yet … for more than 20 years people have been working on making a functional robotic catheter, but nothing has been commercialized yet. So companies like Johnson & Johnson or Boston Scientific, they don’t sell it yet.

Why is that? What’s the obstacle?

Because of reliability. Also, one catheter costs $2000 and is for only one-time use. In surgery, up to four or five catheters might be used and that brings the cost already to $10,000. But more important is the patient safety: patients are exposed to x-ray during the procedure to guide the catheter and many catheters means the patient will be exposed to the x-ray longer.

Is there a natural connection between micro-robotics and medicine?

Yes, of course … because micro-robots are small and the human blood vessels are also small. If you make robots too big, there are many procedures you cannot do. Think of it in terms of an endoscope: if an endoscope is big it can cause pain. But endoscopes are getting smaller and smaller, and some you can even swallow. As robots get smaller, that’s a good thing from a medical perspective, because they can therefore go more deeply into the human body … even the eyes for corneal surgery.

Think even of the Da Vinci … why is it good? Because the human finger is so big … maybe 10mm in diameter, but the Da Vinci device is 3-5mm in diameter and can get inside the body to reach much smaller places than the human hand with less burden to patients.

Does the application of medicine push the field of robotics to be more interdisciplinary?

Yes, medical robotics is a very interdisciplinary area. For example Pierre Dupont conducts research at Boston University and is also now working at the Children’s Hospital. He is not a medical doctor; he is a robotics scientist. Many people in my field work the same way … engineers going into the medical field and making micro-robotics tools to help people and save their lives. If you visit universities engaged in robotics, you will find at least one person working on medical robots. More than 20 years ago, my friend demonstrated using an industrial robot for biopsy or cutting of bone – specifically the hipbone. Many people, especially the elderly, have hipbone joint problems that could be helped with an artificial joint. And sometimes robots can do a better job than the doctors of cutting the bone very precisely … though of course the doctor has to have good knowledge of the subject and operation, and the robot, as I have said, is just a tool.

Medical robotics is a very competitive field. Germany, France, Japan, US … everywhere.

Do you also see people moving from the other direction, from medicine into robotics?

Yes, there are not so many, but there are some. I have met some medical doctors who are very enthusiastic to use robotic technologies for surgeries.

Professor Yamato, who gave one of the plenary lectures at IROS this year, would be a good example?

Yes, he is a good friend, and a medical doctor who is self-taught in robotics …  he understands engineering. Other people are also looking mechanical robotic systems for surgery … maybe they are doing complicated surgeries and want to use more advanced technology, so they are making advances.

Before we finish, I was hoping you could tell us briefly about your recent trip to the Philippines after the typhoon … You were there on behalf of IEEE?

I’m a director of IEEE’s Region 10 – this is the Asia Pacific Region, including Japan, China, South Korea, New Zealand, Australia and other countries. After the typhoon I flew to Manila to meet with the local Region 10 officer and the chairman of the Philippines section of IEEE. The typhoon destroyed all the houses and infrastructure in the affected area; it was completely destructive. So we are working together on humanitarian technology program. We don’t give water or food … we give technology-based support. Like Internet recovery, energy and such things.

We have a lot of knowledge in this area from other disasters like the earthquake that befell a big province in Pakistan several years ago. Using experiences like this one in Pakistan or the tsunami in Indonesia, we are now making a list of priorities of what we should do to assist them. In most cases what we need first is to restore communication, Internet … after the typhoon in the Philippines there was no electricity and we therefore needed solar panels to keep the PCs working.

Is disaster response an especially important area for robotics in your region?

Yes, of course. There are disaster robot teams in Japan and also in IEEE Robotics and Automation Society, there is a technical committee, and we also have a humanitarian technology conference in Region 10. But in the Philippines case, disaster robot systems have played a very minor role so far. Priority is gathering information and restoring communication. In the first stage after a disaster, this is very, very important. But we are looking at later stages when we can bring some robots for taking care of people.

When will that happen?

We will be there in a couple of months … we have to hurry up. People need order to live. For security we want to bring robots to do monitoring, and to take care of the people from a psychological aspect, too. Many people have no houses to live in … it doesn’t feel good. For example we can bring PARO. PARO was made by Dr. Takanori Shidata, who was my graduate student in my lab at Nagoya … we want to bring this kind of robot to the Philippines. The PARO was also used here in Japan after Fukushima to help people with psychological aspects of recovery.

There are various stages where robotics can help after a disaster. We are making our priorities now.

Thank you Toshio for your time!

You are welcome.

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The DelFly Explorer is the first flapping wing Micro Air Vehicle (MAV) that is able to fly with complete autonomy in unknown environments. Weighing just 20 grams and with a wingspan of 28cm, it is equipped with an onboard stereo vision system. The DelFly Explorer can perform an autonomous take-off, keep its height, and avoid obstacles for as long as its battery lasts (~9 minutes). All sensing and processing is performed on board, so no human or offboard computer is in the loop.

Inspired by flying animals, flapping-wing MAVs are highly manoeuvrable, able to quickly transition between multiple flight regimes (such as between hover and forward flying), and are robust to collisions. Their low weight and unobtrusive appearance, as well their ability to fly at low speeds and operate quietly, make them more suitable for use indoors or in the presence of humans than many other aerial platforms. There are many future applications, such as the detection of ripe fruit in green houses, for which flapping wing MAVs would need to fly without human intervention.

However, designing flapping-wing MAVs that are capable of autonomous flight is challenging, because of their small scale and extremely limited payload capabilities. Therefore, previous work in this area either focused on sub-tasks (such as led-following) or out-sourced parts of the sensing and control to external cameras and/or computers.

We achieved the fully autonomous flight of the DelFly Explorer by resolving the following four main challenges:

1. Onboard sensing/processing: We have developed a 4-gram onboard stereo vision system (2 cameras + processor) and 1-gram onboard autopilot with processor, barometer, accelerometers and gyros.
2. Vision algorithms: We developed a new approach to purposive vision, in which the vision algorithms make use of sub-sampling and extract only as many image samples as necessary for subsequent control. As a result, all vision algorithms run at frame rate. Specifically, we designed efficient vision algorithms that can cope with the absence of visual texture, as often happens in indoor environments (see the empty walls in the lecture room as an example). The algorithms also deal with the distortions that are introduced by the combination of the flapping motion and the rolling shutter cameras.
3. Control algorithms: We devised a control algorithm that ensures obstacle-free flight by construction. It takes into account the fact that the DelFly Explorer cannot hover in place by always ensuring an obstacle-free region in which the DelFly can turn around. The height control is based on the onboard barometer.
4. Payload capability: Compared to its predecessor (the 16-gram, 28cm wingspan flapping-wing DelFly II), the Explorer’s payload capability was increased enough to carry the stereo vision system and autopilot. This was achieved both by a redesign of the wings and by a reduction in the number of coils in the brushless motors.

We have performed experiments in various indoor spaces, ranging from lecture rooms to office rooms and lab spaces. Below, you see a part of an autonomous flight in a lecture room at TU Delft. The image has been made by retaining the motion regions every 10 frames in the experimental video. The original experimental video can be seen here.

The current algorithms allow collision-free flight, but do not yet form a complete solution to autonomous exploration. We are working to extend the DelFly’s exploration capabilities so that it can pass through open doors or windows, which it currently avoids.

For more information and videos, please visit the DelFly website.

Reference

“Autonomous Flight of a 20-gram Flapping Wing MAV with a 4-gram Onboard Stereo Vision System”, by C. De Wagter, S. Tijmons, B.D.W. Remes, and G.C.H.E. de Croon, (submitted).

Team

Christophe De Wagter
Sjoerd Tijmons
Bart Remes
Guido de Croon

Contact

g.c.h.e.decroon@tudelft.nl

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Unlike larger robots, microrobots for applications in the body are too small to carry batteries and motors. To address this challenge, we power and control robots made of magnetic materials using external magnetic fields. Developed at ETH Zurich’s  Multi-Scale Robotics Lab (MSRL), the OctoMag is a magnetic manipulation system that uses electromagnetic coils to wirelessly guide microrobots for ophthalmic surgery. 

The OctoMag is capable of generating magnetic forces and torques in three dimensions, and is physically restricted to a single hemisphere to allow easy access for patients and physicians. Using an early OctoMag prototype, ex-vivo experiments were performed in pig eyes to study the navigation tasks required for retinal surgery. Following these experiments, a next-generation system was built to accomodate a small animal head, allowing for in-vivo trials. With this system, mobility experiments were conducted in which a microrobot with a diameter of 285 µm (about four times the width of a hair) was navigated reliably through the eye of a rabbit, demonstrating the feasibility of using this technology in surgical applications.

Robots are capable of exploring many environments that are difficult, if not impossible, for humans to reach; the edges of the solar system, the planet Mars, the inner depths of volcanoes, and bottom of the ocean are just some examples. The goal of these robotic explorers is to obtain knowledge about our universe and to answer fundamental questions about the nature of life on Earth. Recently, micro- and nanotechnologies have fueled an exciting expansion of this field by allowing scientists to use robots to probe life at much smaller scales. Nanorobotic systems for exploring the structures of biological cells, and robotic motion planning strategies for the investigation of protein folding, are two compelling examples of the intermarriage between robotics and nanotechnology. Such efforts and others like them illustrate how several areas of science and engineering are rapidly converging to create a new, interdisciplinary approach to research that promises to revolutionize our understanding of the world around us.

While many envision a future in which intelligent nanorobots navigate throughout our bodies searching for and destroying disease, researchers are still far from realizing such advanced technologies.  However, progress is being made, and the past decade has seen impressive advances in the fabrication, control, and delivery of power to tiny motile devices.

The MiniMag is a research tool for studies at the micro scale. As a scaled-down version of the OctoMag, the MiniMag can be integrated into an upright or inverted microscope. The eight electromagnetic coils are slightly tilted and can be positioned very close to each other due to their smaller size, and, by reducing the magnetic workspace to one cubic centimetre, much higher forces can now be achieved. Combined with high-resolution optics, the MiniMag system allows for single cell manipulation and studies at the tissue level in 3D.

From the microscale to the nanoscale
As size decreases to the nanoscale, wireless magnetic manipulation becomes increasingly challenging. The magnetic force drops by a power of three as it scales with volume, and fluidic drag forces begin to dominate as inertial forces become negligible. While a number of robotic swimming methods have been proposed to aid mobility at relatively small scales, many of these methods rely on reciprocating motions and do not scale downwards.

More than three billion years ago, bacteria evolved a swimming strategy at micrometer dimensions that nature has had difficulty improving upon, and in 1973, H.C. Berg and R.A. Anderson first described a swimming technique that uses rotating helical flagella. Inspired by this work and the flagellar motion of bacteria such as Escherichia Coli, we have recently developed artificial bacterial flagella (ABF). Our ABF represents the first demonstration of wireless swimming microrobots similar in size and geometry to natural bacterial flagella, and are many orders of magnitude smaller than existing artificial helical swimmers. With the help of 3D-laser-nanolithography, arrays of thousands of such swimmers can now be fabricated. A careful choice of materials allows for cellular interaction, and fluorescent labeling of the device assists with localization and tracking. We are pursuing applications such as the treatment of breast cancer and cerebral infarctions.

The potential impact of this technology on society is high, particularly for biomedical applications, though many challenges remain in developing micro and nanorobots that will be useful to society. An overarching requirement for achieving breakthroughs in this area is the need to bring together expertise from a wide variety of science and engineering disciplines.  Robotics brings expertise in the planning and control of mechanisms with many degrees of freedom in uncertain environments. Nanotechnology teaches innovative approaches to fabricating nanoscale machines. In addition, biomedical imaging advances are needed, as is fundamental insight into the nature of fluid dynamics at very small scales.  Medical professionals must be tightly integrated into the development cycle, and experts in developing business models and intellectual property must be closely consulted.

About the researchers
Brad Nelson’s Multi-Scale Robotics Lab (MSRL) at the Institute of Robotics and Intelligent Systems, ETH Zurich, Switzerland, is a highly multi-disciplinary research group that leverages advanced robotics techniques to create intelligent machines that operate at micro- and nanometer scales.  At the MSRL, a team of nearly 30 scientists pursues a dynamic, robotics-oriented research program involving several emerging areas of science and technology.  The technical backgrounds of the scientists in the lab span such diverse fields as materials science, physics, biology, electrical and mechanical engineering, and computer science.

The materials scientists in the lab focus mainly on developing the tools and processes required to fabricate and assemble microscale robots and nanoscale robotic components.  Many of these systems are then used in the study of biological environments, including the investigation of molecular structures, cellular systems, and organism behavior.  Other members of the MSRL research team are focused on the design and implementation of systems that wirelessly control these microrobots.  Potential applications are numerous and diverse, including microrobotically-assisted surgery, magnetic micromanipulation at the cellular level, low Reynolds number locomotion, wireless power delivery, electrostimulation of biological materials, and micro- and nanostructure fabrication and characterization.

The MSRL develops systems for controlling micro- and nanorobots in liquid and pursues various applications for these devices.

[Edited by Hallie Siegel]

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

I’m from computer science, moved to robotics and now live in bio-engineering. My home is a mix of processors, sensors, actuators, cells and nanoparticles. Science has no official border, yet I’ve had to learn a new language and culture for each discipline. Grants are the visas you need to explore new places. Grants are nearly never given to outsiders, only to the locals, the experts with preliminary data. Luckily, some organizations like HFSP, give wild cards to people like me, regardless of their origin.

Like a newcomer eager to fit in and unaware of the challenges, I started my integration, attending all the seminars and resurfacing lost skills with Khan Academy. A computer scientist could become a roboticist and a roboticist could be a bio-engineer, why not? We are all researchers after all. Then I realized that integration takes years — longer than a postdoc — and you risk losing your identity in the process. At parties, when people asked what I did, I would go into a tirade about computers, flying robots and nanoparticles to cure cancer. Oh that’s interesting, like being quarter Japanese, Italian, Irish and Egyptian.

A brilliant professor then told me, “You need to be an expert in something. That is your identity.” I am a swarm engineer. I like to discover new ways in which large numbers of simple agents can work together to perform complex tasks. I use computer tools like crowdsourcing and machine learning to discover swarm strategies and apply them to real world systems such as robotics and nanomedicine. I’ve gone from trying to integrate into new fields to integrating fields.

There are no travel guides in cross-disciplinary science, it’s all unblazed trails. That is part of the excitement, bridges need to be built, and you’re the first one on the other side of the river. If you want to learn a new field, you need to go there and understand the language and culture. You won’t understand what is challenging until you try, and they won’t warn you because it is obvious. Since you are bi-lingual, you need to explain your work in their language, don’t expect them to know anything of your origin or the challenges you face. Find a nurturing and open-minded environment to welcome you (thank you Bhatia Lab!). Identify your expertise and use that as an anchor in everything you do (thank you Nagpal Lab!). Finally, don’t naturalize, fuse your backgrounds. At least, that is how I see things now.

This summer I’ll be at the Lindau Nobel Laureates Meeting, listening to 35 Nobel Laureates in chemistry. It looks like I’ll be learning a new language, maybe there is some swarm engineering to do there? I just hope that the person checking my passport at the next academic border (i.e. faculty search, grant office) will not look at the stamps, and wonder why I’ve been to so many different places.

Here is a great summary made by Ilana Schoenfeld that explains swarm engineering and presents some of my work.

Flies have small brains that would not be able to process high-resolution images such as those that we see with our own eyes. Instead, they’ve perfected the use of compound eyes, composed of a dense mosaic of tiny eye-like structures called ommatidia. Each ommatidium consists of a microlense that focuses light from a specific section of the insect’s field of view onto an independent set of photoreceptors. Think of it as having many low-resolution cameras pointing in different directions. The result is a vision system with low spatial resolution (i.e. it can’t see details), but a wide field of view (i.e. it can see all around). By comparing information across the different ommatidia, flies can extract temporal information useful for detecting motion. This motion information, also called optic flow, is what allows flies to navigate, take-off, land and avoid obstacles while using very little processing power.

Inspired by the fly’s vision system, the Curved Artificial Compound Eye (CurvACE) published today in the prestigious journal PNAS can enable a large range of applications that require motion detection using a small plug-and-play device. As shown in the video below, you could use these sensors to control small robots navigating an environment, even in the dark, or equip a small autonomous flying robot with limited payload. Other applications include home automation, surveillance, medical instruments, prosthetic devices, and smart clothing.

The artificial compound eye features a panoramic, hemispherical field of view with a resolution identical to that of the fruitfly in less than 1 mm thickness. Additionally, it can extract images 3 times faster than a fruitfly, and includes neuromorphic photoreceptors that allow motion perception in a wide range of environments from a sunny day to moon light. To build the sensors, the researchers align an array of microlenses, an array of photodetectors, and a flexible PCB that mechanically supports and electrically connects the ensemble. The panoramic field of view is provided by dicing the rigid parts of the ommatidia, thereby allowing the mechanical bending of the sensor. The necessary components for signal readout and processing are embedded in the curvature of the sensor.

CurvACE is a European project bringing together the Laboratory of Intelligent Systems in EPFL (Switzerland), the Laboratory of Biorobotics in the University of Aix-Marseille (France), the Fraunhofer Institute of Applied Optics and Precision Engineering (Germany), and the Laboratory of Cognitive Sciences in the University of Tübingen (Germany).

Don’t miss the next ROBOTS podcast for my interview with the researchers behind this new artificial compound eye.

Fabrication
Rob Wood’s Microrobotics Laboratory at Harvard has a long history of developing small flying robots using a clever fabrication technique intended for easy and cheap mass-production. The method described in the video below is inspired from pop-up books that you can cut and fold to make articulated three-dimensional structures. By sandwiching flexible materials between laser-cut carbon fiber layers, they are able to rapidly fabricate robot skeletons that can be folded and locked into shape by soldering dedicated attachment points. The skeleton of the controllable robot is augmented with two piezoelectric muscles to differentially drive the wings. These muscles are made of special materials that contract and expand when electricity is applied to them. Power is provided by an external cable.

Control
To control its position, the robot needs to change how it beats its wings. Beating the left wing harder than the right wing will produce a torque on the robot’s body. The robot is inherently unstable and a very fast and precise control is needed to keep it aloft. It would be nearly impossible for a human to manually control the wing motions or preset them based on flight dynamics. Instead, the robot continuously compares its actual position to its intended position and corrects the wing motions accordingly (closed-loop control). The position of the robot is provided by an external camera system which tracks markers on the body of the robot. Using this technique the robot is able to stay in place, and move to a designated location. This is a remarkable feat for such a small and highly dynamic flyer. Previous version of the robot had been seen taking off and controlling altitude:

Applications
This work is part of the Robobees project which brings together 10 laboratories to fabricate, control and power bio-inspired roboinsects that can function in swarms. Applications, although still a long way in the future, include autonomously pollinating a field of crops, search and rescue, hazardous environment exploration, military surveillance, high resolution weather and climate mapping and traffic monitoring.

Listen to our podcast interviews with the authors of the paper including Kevin Ma, Pakpong Chirarattananon and Sawyer Fuller.

Links:

• Official Press Release
• Controlled Flight of a Biologically Inspired, Insect-Scale Robot, Kevin Y. Ma, Pakpong Chirarattananon, Sawyer B. Fuller, Robert J. Wood, SCIENCE 2013

Photo Credits: Kevin Ma and Pakpong Chirarattananon, Harvard University.

At the International Conference on Intelligent Robots and Systems (IROS) last October, I saw an excellent talk by Dr. Kaori Kuribayashi-Shigetomi from the University of Tokyo about “Cell Origami”. Her work, which was recently published in PLOS One, uses the natural pulling force that cells produce on surfaces where they grow to fold smartly cut and positioned 2D sheets into desired 3D structures. The process, demonstrated in the video below, shows cells grown on top of engineered microplates fixed to a flat surface. To fold the structure, simply detach the microplates from the surface and allow the cells to pull them into a 3D structure. The cells in this case act like a rubber-band. Such 3D structures could be useful for a variety of applications including tissue engineering or 3D assembly at the microscale. By using the natural beats produced by heart cells (cardiomyocytes) to actuate the microplates, she is then able to make a “flapping robot”. The end of the video shows that these 3D structures can be mass produced with 1200 structures folded per cm².