By Peter Rüegg

Ecologists are increasingly using traces of genetic material left behind by living organisms left behind in the environment, called environmental DNA (eDNA), to catalogue and monitor biodiversity. Based on these DNA traces, researchers can determine which species are present in a certain area.

Obtaining samples from water or soil is easy, but other habitats – such as the forest canopy – are difficult for researchers to access. As a result, many species remain untracked in poorly explored areas.

Researchers at ETH Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, and the company SPYGEN have partnered to develop a special drone that can autonomously collect samples on tree branches.

(Video: ETH Zürich)

How the drone collects material

The drone is equipped with adhesive strips. When the aircraft lands on a branch, material from the branch sticks to these strips. Researchers can then extract DNA in the lab, analyse it and assign it to genetic matches of the various organisms using database comparisons.

But not all branches are the same: they vary in terms of their thickness and elasticity. Branches also bend and rebound when a drone lands on them. Programming the aircraft in such a way that it can still approach a branch autonomously and remain stable on it long enough to take samples was a major challenge for the roboticists.

“Landing on branches requires complex control,” explains Stefano Mintchev, Professor of Environmental Robotics at ETH Zurich and WSL. Initially, the drone does not know how flexible a branch is, so the researchers fitted it with a force sensing cage. This allows the drone to measure this factor at the scene and incorporate it into its flight manoeuvre.

Scheme: DNA is extracted from the collected branch material, amplified, sequenced and the sequences found are compared with databases. This allows the species to be identified. (Graphic: Stefano Mintchev / ETH Zürich)

Preparing rainforest operations at Zoo Zurich

Researchers have tested their new device on seven tree species. In the samples, they found DNA from 21 distinct groups of organisms, or taxa, including birds, mammals and insects. “This is encouraging, because it shows that the collection technique works,“ says Mintchev, who co-​authored the study that has appeared in the journal Science Robotics.

The researchers now want to improve their drone further to get it ready for a competition in which the aim is to detect as many different species as possible across 100 hectares of rainforest in Singapore in 24 hours.

To test the drone’s efficiency under conditions similar to those it will experience at the competition, Mintchev and his team are currently working at the Zoo Zurich’s Masoala Rainforest. “Here we have the advantage of knowing which species are present, which will help us to better assess how thorough we are in capturing all eDNA traces with this technique or if we’re missing something,“ Mintchev says.

For this event, however, the collection device must become more efficient and mobilize faster. In the tests in Switzerland, the drone collected material from seven trees in three days; in Singapore, it must be able to fly to and collect samples from ten times as many trees in just one day.

Collecting samples in a natural rainforest, however, presents the researchers with even tougher challenges. Frequent rain washes eDNA off surfaces, while wind and clouds impede drone operation. “We are therefore very curious to see whether our sampling method will also prove itself under extreme conditions in the tropics,” Mintchev says.

• PAPER – Drone-​assisted collection of environmental DNA from tree branches for biodiversity monitoring. Aucone E, Kirchgeorg E, Valentini A, Pellissier L, Deiner K, and Mintchev S. Science Robotics, 18 January 2023. DOI 10.1126/scirobotics.add5762

Elvis Nava is a fellow at ETH’ Zurich’s AI center as well as a doctoral student at the Institute of Neuroinformatics and in the Soft Robotics Lab. (Photograph: Daniel Winkler / ETH Zurich)

By Christoph Elhardt

In ETH Zurich’s Soft Robotics Lab, a white robot hand reaches for a beer can, lifts it up and moves it to a glass at the other end of the table. There, the hand carefully tilts the can to the right and pours the sparkling, gold-coloured liquid into the glass without spilling it. Cheers!

Computer scientist Elvis Nava is the person controlling the robot hand developed by ETH start-up Faive Robotics. The 26-year-old doctoral student’s own hand hovers over a surface equipped with sensors and a camera. The robot hand follows Nava’s hand movement. When he spreads his fingers, the robot does the same. And when he points at something, the robot hand follows suit.

But for Nava, this is only the beginning: “We hope that in future, the robot will be able to do something without our having to explain exactly how,” he says. He wants to teach machines to carry out written and oral commands. His goal is to make them so intelligent that they can quickly acquire new abilities, understand people and help them with different tasks.

Functions that currently require specific instructions from programmers will then be controlled by simple commands such as “pour me a beer” or “hand me the apple”. To achieve this goal, Nava received a doctoral fellowship from ETH Zurich’s AI Center in 2021: this program promotes talents that bridges different research disciplines to develop new AI applications. In addition, the Italian – who grew up in Bergamo – is doing his doctorate at Benjamin Grewe’s professorship of neuroinformatics and in Robert Katzschmann’s lab for soft robotics.

Developed by the ETH start-​up Faive Robotics, the robot hand imitates the movements of a human hand. (Video: Faive Robotics)

Combining sensory stimuli

But how do you get a machine to carry out commands? What does this combination of artificial intelligence and robotics look like? To answer these questions, it is crucial to understand the human brain.

We perceive our environment by combining different sensory stimuli. Usually, our brain effortlessly integrates images, sounds, smells, tastes and haptic stimuli into a coherent overall impression. This ability enables us to quickly adapt to new situations. We intuitively know how to apply acquired knowledge to unfamiliar tasks.

“Computers and robots often lack this ability,” Nava says. Thanks to machine learning, computer programs today may write texts, have conversations or paint pictures, and robots may move quickly and independently through difficult terrain, but the underlying learning algorithms are usually based on only one data source. They are – to use a computer science term – not multimodal.

For Nava, this is precisely what stands in the way of more intelligent robots: “Algorithms are often trained for just one set of functions, using large data sets that are available online. While this enables language processing models to use the word ‘cat’ in a grammatically correct way, they don’t know what a cat looks like. And robots can move effectively but usually lack the capacity for speech and image recognition.”

“Every couple of years, our discipline changes the way we think about what it means to be a researcher,” Elvis Nava says. (Video: ETH AI Center)

Robots have to go to preschool

This is why Nava is developing learning algorithms for robots that teach them exactly that: to combine information from different sources. “When I tell a robot arm to ‘hand me the apple on the table,’ it has to connect the word ‘apple’ to the visual features of an apple. What’s more, it has to recognise the apple on the table and know how to grab it.”

But how does the Nava teach the robot arm to do all that? In simple terms, he sends it to a two-stage training camp. First, the robot acquires general abilities such as speech and image recognition as well as simple hand movements in a kind of preschool.

Open-source models that have been trained using giant text, image and video data sets are already available for these abilities. Researchers feed, say, an image recognition algorithm with thousands of images labelled ‘dog’ or ‘cat.’ Then, the algorithm learns independently what features – in this case pixel structures – constitute an image of a cat or a dog.

A new learning algorithm for robots

Nava’s job is to combine the best available models into a learning algorithm, which has to translate different data, images, texts or spatial information into a uniform command language for the robot arm. “In the model, the same vector represents both the word ‘beer’ and images labelled ‘beer’,” Nava says. That way, the robot knows what to reach for when it receives the command “pour me a beer”.

Researchers who deal with artificial intelligence on a deeper level have known for a while that integrating different data sources and models holds a lot of promise. However, the corresponding models have only recently become available and publicly accessible. What’s more, there is now enough computing power to get them up and running in tandem as well.

When Nava talks about these things, they sound simple and intuitive. But that’s deceptive: “You have to know the newest models really well, but that’s not enough; sometimes getting them up and running in tandem is an art rather than a science,” he says. It’s tricky problems like these that especially interest Nava. He can work on them for hours, continuously trying out new solutions.

Nava spends the majority of his time coding. (Photograph: Elvis Nava)

Nava evaluates his learning algorithm. The results of the experiment in a nutshell. (Photograph: Elvis Nava)

Special training: Imitating humans

Once the robot arm has completed preschool and has learnt to understand speech, recognise images and carry out simple movements, Nava sends it to special training. There, the machine learns to, say, imitate the movements of a human hand when pouring a glass of beer. “As this involves very specific sequences of movements, existing models no longer suffice,” Nava says.

Instead, he shows his learning algorithm a video of a hand pouring a glass of beer. Based on just a few examples, the robot then tries to imitate these movements, drawing on what it has learnt in preschool. Without prior knowledge, it simply wouldn’t be able to imitate such a complex sequence of movements.

“If the robot manages to pour the beer without spilling, we tell it ‘well done’ and it memorises the sequence of movements,” Nava says. This method is known as reinforcement learning in technical jargon.

Elvis Nava teaches robots to carry out oral commands such as “pour me a beer”. (Photograph: Daniel Winkler / ETH Zürich)

Foundations for robotic helpers

With this two-stage learning strategy, Nava hopes to get a little closer to realising the dream of creating an intelligent machine. How far it will take him, he does not yet know. “It’s unclear whether this approach will enable robots to carry out tasks we haven’t shown them before.”

It is much more probable that we will see robotic helpers that carry out oral commands and fulfil tasks they are already familiar with or that closely resemble them. Nava avoids making predictions as to how long it will take before these applications can be used in areas such as the care sector or construction.

Developments in the field of artificial intelligence are too fast and unpredictable. In fact, Nava would be quite happy if the robot would just hand him the beer he will politely request after his dissertation defence.

Magnetic bacteria (grey) can squeeze through narrow intercellular spaces to cross the blood vessel wall and infiltrate tumours. (Visualisations: Yimo Yan / ETH Zurich)

By Fabio Bergamin

Scientists around the world are researching how anti-cancer drugs can most efficiently reach the tumours they target. One possibility is to use modified bacteria as “ferries” to carry the drugs through the bloodstream to the tumours. Researchers at ETH Zurich have now succeeded in controlling certain bacteria so that they can effectively cross the blood vessel wall and infiltrate tumour tissue.

Led by Simone Schürle, Professor of Responsive Biomedical Systems, the ETH Zurich researchers chose to work with bacteria that are naturally magnetic due to iron oxide particles they contain. These bacteria of the genus Magnetospirillum respond to magnetic fields and can be controlled by magnets from outside the body; for more on this, see an earlier article in ETH News.

Exploiting temporary gaps

In cell cultures and in mice, Schürle and her team have now shown that a rotating magnetic field applied at the tumour improves the bacteria’s ability to cross the vascular wall near the cancerous growth. At the vascular wall, the rotating magnetic field propels the bacteria forward in a circular motion.

To better understand the mechanism to cross the vessel wall works, a detailed look is necessary: The blood vessel wall consists of a layer of cells and serves as a barrier between the bloodstream and the tumour tissue, which is permeated by many small blood vessels. Narrow spaces between these cells allow certain molecules from the to pass through the vessel wall. How large these intercellular spaces are is regulated by the cells of the vessel wall, and they can be temporarily wide enough to allow even bacteria to pass through the vessel wall.

Strong propulsion and high probability

With the help of experiments and computer simulations, the ETH Zurich researchers were able to show that propelling the bacteria using a rotating magnetic field is effective for three reasons. First, propulsion via a rotating magnetic field is ten times more powerful than propulsion via a static magnetic field. The latter merely sets the direction and the bacteria have to move under their own power.

The second and most critical reason is that bacteria driven by the rotating magnetic field are constantly in motion, travelling along the vascular wall. This makes them more likely to encounter the gaps that briefly open between vessel wall cells compared to other propulsion types, in which the bacteria’s motion is less explorative. And third, unlike other methods, the bacteria do not need to be tracked via imaging. Once the magnetic field is positioned over the tumour, it does not need to be readjusted.

“Cargo” accumulates in tumour tissue

“We make use of the bacteria’s natural and autonomous locomotion as well,” Schürle explains. “Once the bacteria have passed through the blood vessel wall and are in the tumour, they can independently migrate deep into its interior.” For this reason, the scientists use the propulsion via the external magnetic field for just one hour – long enough for the bacteria to efficiently pass through the vascular wall and reach the tumour.

Such bacteria could carry anti-cancer drugs in the future. In their cell culture studies, the ETH Zurich researchers simulated this application by attaching liposomes (nanospheres of fat-like substances) to the bacteria. They tagged these liposomes with a fluorescent dye, which allowed them to demonstrate in the Petri dish that the bacteria had indeed delivered their “cargo” inside the cancerous tissue, where it accumulated. In a future medical application, the liposomes would be filled with a drug.

Bacterial cancer therapy

Using bacteria as ferries for drugs is one of two ways that bacteria can help in the fight against cancer. The other approach is over a hundred years old and currently experiencing a revival: using the natural propensity of certain species of bacteria to damage tumour cells. This may involve several mechanisms. In any case, it is known that the bacteria stimulate certain cells of the immune system, which then eliminate the tumour.

“We think that we can increase the efficacy of bacterial cancer therapy by using a engineering approach.”

– Simone Schürle

Multiple research projects are currently investigating the efficacy of E. coli bacteria against tumours. Today, it is possible to modify bacteria using synthetic biology to optimise their therapeutic effect, reduce side effects and make them safer.

Making non-magnetic bacteria magnetic

Yet to use the inherent properties of bacteria in cancer therapy, the question of how these bacteria can reach the tumour efficiently still remains. While it is possible to inject the bacteria directly into tumours near the surface of the body, this is not possible for tumours deep inside the body. That is where Professor Schürle’s microrobotic control comes in. “We believe we can use our engineering approach to increase the efficacy of bacterial cancer therapy,” she says.

E. coli used in the cancer studies is not magnetic and thus cannot be propelled and controlled by a magnetic field. In general, magnetic responsiveness is a very rare phenomenon among bacteria. Magnetospirillum is one of the few genera of bacteria that have this property.

Schürle therefore wants to make E. coli bacteria magnetic as well. This could one day make it possible to use a magnetic field to control clinically used therapeutic bacteria that have no natural magnetism.

• PAPER – Magnetic torque–driven living microrobots for increased tumor infiltration. Gwisai T, Mirkhani N, Christiansen MG, Nguyen TT, Ling V, and Schuerle S. Science Robotics, vol.7(71)

Researchers Matthias Hofer, Michael Muehlebach and Raffaello D’Andrea have developed the one-wheel Cubli, a three-dimensional pendulum system that can balance on its pivot using a single reaction wheel. How is it possible to stabilize the two tilt angles of the system with only a single reaction wheel?

The key is to design the system such that the inertia in one direction is higher than in the other direction by attaching two masses far away from the center. As a consequence, the system moves faster in the direction with the lower inertia and slower in the direction with the higher inertia. The controller can leverage this property and stabilize both directions simultaneously.

This work was carried out at the Institute for Dynamic Systems and Control, ETH Zurich, Switzerland.

Almost a decade has passed since the first Cubli

The Cubli robot started with a simple idea: Can we build a 15cm sided cube that can jump up, balance on its corner, and walk across our desk using off-the-shelf motors, batteries, and electronic components? The educational article Cubli – A cube that can jump up, balance, and walk across your desk shows all the design principles and prototypes that led to the development of the robot.

Cubli, from ETH Zurich.

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

The legged robot ANYmal on the rocky path to the summit of Mount Etzel, which stands 1,098 metres above sea level. (Photo: Takahiro Miki)

By Christoph Elhardt

Steep sections on slippery ground, high steps, scree and forest trails full of roots: the path up the 1,098-​metre-high Mount Etzel at the southern end of Lake Zurich is peppered with numerous obstacles. But ANYmal, the quadrupedal robot from the Robotic Systems Lab at ETH Zurich, overcomes the 120 vertical metres effortlessly in a 31-​minute hike. That’s 4 minutes faster than the estimated duration for human hikers – and with no falls or missteps.

This is made possible by a new control technology, which researchers at ETH Zurich led by robotics professor Marco Hutter recently presented in the journal Science Robotics. “The robot has learned to combine visual perception of its environment with proprioception – its sense of touch – based on direct leg contact. This allows it to tackle rough terrain faster, more efficiently and, above all, more robustly,” Hutter says. In the future, ANYmal can be used anywhere that is too dangerous for humans or too impassable for other robots.

Video: Nicole Davidson / ETH Zurich

Perceiving the environment accurately

To navigate difficult terrain, humans and animals quite automatically combine the visual perception of their environment with the proprioception of their legs and hands. This allows them to easily handle slippery or soft ground and move around with confidence, even when visibility is low. Until now, legged robots have been able to do this only to a limited extent.

“The reason is that the information about the immediate environment recorded by laser sensors and cameras is often incomplete and ambiguous,” explains Takahiro Miki, a doctoral student in Hutter’s group and lead author of the study. For example, tall grass, shallow puddles or snow appear as insurmountable obstacles or are partially invisible, even though the robot could actually traverse them. In addition, the robot’s view can be obscured in the field by difficult lighting conditions, dust or fog.

“That’s why robots like ANYmal have to be able to decide for themselves when to trust the visual perception of their environment and move forward briskly, and when it is better to proceed cautiously and with small steps,” Miki says. “And that’s the big challenge.”

A virtual training camp

Thanks to a new controller based on a neural network, the legged robot ANYmal, which was developed by ETH Zurich researchers and commercialized by the ETH spin-​off ANYbotics, is now able to combine external and proprioceptive perception for the first time. Before the robot could put its capabilities to the test in the real world, the scientists exposed the system to numerous obstacles and sources of error in a virtual training camp. This let the network learn the ideal way for the robot to overcome obstacles, as well as when it can rely on environmental data – and when it would do better to ignore that data.

“With this training, the robot is able to master the most difficult natural terrain without having seen it before,” says ETH Zurich Professor Hutter. This works even if the sensor data on the immediate environment is ambiguous or vague. ANYmal then plays it safe and relies on its proprioception. According to Hutter, this allows the robot to combine the best of both worlds: the speed and efficiency of external sensing and the safety of proprioceptive sensing.

Use under extreme conditions

Whether after an earthquake, after a nuclear disaster, or during a forest fire, robots like ANYmal can be used primarily wherever it is too dangerous for humans and where other robots cannot cope with the difficult terrain.

In September of last year, ANYmal was able to demonstrate just how well the new control technology works at the DARPA Subterranean Challenge, the world’s best-​known robotics competition. The ETH Zurich robot automatically and quickly overcame numerous obstacles and difficult terrain while autonomously exploring an underground system of narrow tunnels, caves, and urban infrastructure. This was a major part of why the ETH Zurich researchers, as part of the CERBERUS team, took first place with a prize of 2 million dollars.

• PAPER – Learning robust perceptive locomotion for quadrupedal robots in the wild. Miki T, Lee J, Hwangbo J, Wellhausen L. Science Robotics 2022, doi: 10.1126/scirobotics.abk2822

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.

Welby Altidor, Executive Creative Director of Creation, Cirque du Soleil (L) and Benjamin Dupont (R). Source: 2016 NYCDFF

SPARKED: A Live Interaction Between Humans and Quadcopters won the 2016 New York City Drone Film Festival (NYCDFF) Featuring Drones category.

NYCDFF is the world’s first event exclusively dedicated to celebrating the art of drone cinematography. The festival offers an international platform for filmmakers from every corner of the globe to exhibit their work in front of industry professionals and the drone cinema fan community. 

Watch their award winning film here:

Cirque du Soleil, ETH Zurich, and ETH spinoff Verity Studios partnered to develop the short film that features 10 quadcopters in a flying dance performance. The collaboration resulted in a unique, interactive choreography where humans and drones move in sync. Precise computer control allows for a large performance and movement vocabulary of the quadcopters and opens the door to many more applications in the future.

You can also watch a short film about the making of SPARKED here:

If you like this post, you also may also enjoy reading:

• New quadrocopter video points to a future for flying machines in entertainment
• Quadrotors vs CGI: A Q&A with the makers of Sparked

Precisely controlled elastic actuators allow for temporary energy storage – in fact this robotic system consumes 10 times less power than other hydraulic systems. Weighing in at just 26 kg, it can be handled by a single operator, but operates autonomously at a speed of 2km per hour walking or running. Potential applications for such a highly mobile robot include: inspection of industrial, construction, or polluted environments, search and rescue operations, security, or even the entertainment industry.

Further reading:
http://www.leggedrobotics.ethz.ch/doku.php?id=robots:starleth:starleth
http://www.leggedrobotics.ethz.ch/doku.php?id=robots:scarleth
http://www.leggedrobotics.ethz.ch/lib/exe/fetch.php?media=robots:starleth:description:201401_descriptiontransporter.pdf

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Rock Print, Architectural installation at the Chicago Architecture Biennial 2015 from Gramazio Kohler Research, ETH Zurich and the Self-Assembly Lab, MIT

Inspired to take 3D printing technology to new heights, ETH Zurich and MIT researchers create “Rock Print” — a full-scale architectural installation on display at the Chicago Architecture Biennial until January 3, 2016.

Standing over 13 feet (4 metres) high in the Chicago Cultural Center, the monolithic Rock Print installation with its rough and elegant contours confirms that collaboration inspires “State of the Art Architecture” – the theme of the inaugural Chicago Architecture Biennial.

Born out of a 2012 University of Chicago conference that brought architects, engineers, material scientists, and physicists together, Rock Print demonstrates a principle called “jamming” that refers to aggregate granular materials, like gravel that are quite literally crammed together in such a way that they hold their form and shape like a solid, even though their molecular properties are closer (in terms of behaviour) to a liquid substance.

“Jamming” together, researchers from Gramazio Kohler Research, ETH Zurich and Skylar Tibbits’ Self-Assembly Lab at the Massachusetts Institute of Technology (MIT) produced, Rock Print – a zero waste and fully reversible architectural installation for the inauguration of the Chicago Architecture Biennial that opened on 3 October 2015.

Inspired by 3D print technology

“Rock Print is a proof of concept that takes current robotic fabrication technology and applies it to a full-scale architectural project,” said Andreas Thoma, ETH Zurich.

Petrus Aejmelaeus-Lindstroem, lead researcher for the project at ETH Zurich added, “The project shows the capacity of a 3D printing process to create a geometrically-complex construction using two simple components found in everyday life – string and rocks.”

The environmentally conscious ETH and MIT installation team used a custom robotic fabrication setup to lay down nearly 5 miles (9.1 km) of a recycled textile string in a complex pattern guided by a specifically designed algorithm. Like making lasagne, the string is alternated with layers of a loose standard concrete aggregate (rocks) from the Swiss company Misapor. The company makes self-insulating concrete using crushed glass, additives, and a heating process that expands the glass into a foam-like aggregate of mostly air.

While the foam glass is a fraction of the weight of conventional gravel aggregate, Rock Print weighs in at slightly less than one tonne (970 kg to be exact). The weight is a delicate balance – a lighter weight material is necessary for an indoor installation, but the structure of the installation depends on weight to provide strength to the compressional forces that maintain its shape and to compensate for the relatively weak tensional forces.

New possibilities for the future of architecture

Matthias Kohler, who also serves as the Director of the National Competence Centre in Research (NCCR) Digital Fabrication, commented on how 3D printing technology may influence architecture in the future stating, “3D printing technology is an inspiration for the future of architecture as it brings together resource efficient additive building principles with new possibilities for design. Such technology enables production of complex forms and intricate details of building elements at a minimal cost. Today’s commercially available 3D printing technologies are not yet suitable for the scale needed for architecture or its economic and structural demands.”

The Rock Print installation challenges and expands the scope of 3D printing to an architectural scale by introducing robotic fabrication and the use of inexpensive, reconfigurable bulk construction materials. This approach attempts to open new possibilities for future architecture – using advanced digital fabrication technology to build with sustainable and locally available materials.

Kohler says, “There is still a lot of interdisciplinary research needed to fully understand and leverage future digital fabrication principles at a full building scale, but after ten intensive years of research in the field, I am positive that such new principles will not only lead to exciting architecture projects, but also to a new digital building culture – possibly to a socially relevant transformation of our built environment.”

Gramazio Kohler Research, ETH Zurich

The research group headed by Professors Fabio Gramazio and Matthias Kohler at ETH Zurich examines the changes in architectural production that result from the introduction of digital manufacturing techniques. The main focus is ground-breaking research into computational design, constructive systems and their synthesis through the use of novel robotic fabrication technologies. Lindstroem and Thoma indicated that Rock Print was made possible through the collaborative knowledge of architects, engineers, and computational physicists. Prof. Dr. Hans J. Herrmann and Dr. Falk Wittel from ETH Zurich’s Institute for Building Materials and Prof. Dr. Heinrich Jaeger from the University of Chicago consulted on the project.

Gramazio Kohler Research – Rock Print project page

Chicago Architecture Biennial 2015

Rock Print is on display throughout the biennial that runs through 3 January 2016 in the Chicago Cultural Center – the former public library across from the stunning Millennium Park in the heart of the city. Famous for its contemporary architecture and landmark skyscrapers, the Chicago Architecture Biennial celebrates with the theme, “State of the Art in Architecture” providing a platform for ground-breaking architectural projects and spatial experiments that demonstrate how creativity and innovation can radically transform our lived experience. It offers an opportunity to take stock of more than 70 architectural projects and experiments from 30 countries around the world. Rock Print represents the Swiss-US collaboration at the forefront of innovation in architecture.

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The adaptive solar façade is assembled on the south side of the House of Natural Resources. (Photo: Marco Carocari)

By Arno Schlüter
Today, building envelopes tend to be static and unable to adapt to changing conditions. Now, for the first time, an adaptable façade has been used for the newly inaugurated House of Natural Resources (HoNR) that produces electricity and regulates light and heat generation.

The envelope of a building is of great importance to its energy balance, and insulation and air-tightness have improved significantly in recent years. But there is also significant untapped potential when it comes to contributing to the transition of our energy system towards renewable energy sources: the building envelope of a building, particularly the façade, can be designed to recover heat and generate electricity.

From rigid to dynamic structures

As the boundary between interior and exterior spaces, the façade influences the air, light and heat balance of a building significantly – and thus has a direct impact on the comfort of users. Both spaces are stochastic by nature: they change constantly and conditions are at best only vaguely predictable. And yet the envelope of a building is usually static, focusing on only one or just a few different situations. Today’s building envelope is rarely adaptable to changes in weather or the use of a room. This considerable potential for energy conservation and generation, as well as improved comfort, remains unused.

At the Chair of Architecture and Building Systems, we are researching approaches to make the building envelope more dynamic, efficient and adaptive. One example is the adaptive solar façade, which consists of individual modules mounted on a cable network on the façade. By adjusting the amount of solar radiation through the window, they can control the light and heat of the internal space and at the same time produce electricity through highly efficient thin-film solar cell modules. The adaptive solar façade is also very lightweight, so in contrast to traditional photovoltaic panels it can be mounted almost anywhere, including on existing buildings.

Soft robotics for adaptability

The soft actuator can move the module. (Photo: Professorship of Architecture and Building Systems)

The modules are moveable thanks to a new device, the soft robotic actuator, which originates from a new and promising field of robotics, soft robotics. It is made of flexible materials that take multiple forms when the pressure in the special chambers change. Such actuators are normally used mainly for prosthetic and biomimetic robots; we are now exploring and developing them for future energy and climate systems in buildings.

Our soft actuator is manufactured with a specially developed hollow casting process and the chamber is then filled with air. Valves control the air flow by pumping or releasing air to deform the actuator and thus move the solar element selectively. With soft actuators, we can control each adaptive solar façade module individually and rotate it on two axes, either on its own or in groups. This enables the modules to track the sun’s movement and generate power, use or limit solar power, create privacy or open up the view. An intelligent and adaptive regulator allows the façade to adapt to changing weather conditions and the habits and wishes of the user.

Prototype at the House of Natural Resources

A view of the adaptive solar façade from inside the building. (Photo: Marco Carocari)

Without soft actuators, such functionality would be possible only through a complex combination of several mechanical parts. These would be less durable and more expensive – making it unlikely that they would achieve widespread use in façades. In contrast, our actuator costs only a few francs when produced industrially. The soft actuator has been proven to be robust in cyclic tests in the laboratory; now it has to prove that it is just as effective in the harsh conditions of a building façade. To test this, along with various other factors, we have assembled a prototype façade of 50 modules on the south side of the House of Natural Resources (HoNR).

The module uses highly efficient copper indium gallium selenide (CIGS) thin-film solar cells for top performance: the solar cells are developed by the EMPA spin-off Flisom [1], our industrial partner in the project. First life-cycle calculations have shown that it would take only 18 months for the adaptive solar façade to offset the CO2 emitted in the module’s manufacture.

As part of the EU Climate-KIC’s Building Technology Accelerator flagship project [2], we are currently investigating how and in what form the adaptive solar façade, and thus the soft actuator, can be developed into a marketable product. If this is successful, our adaptive façade could contribute to the efficient generation of building energy and thus to energy transition.

Further information

House of Natural Resources HoNR

Website of the Chair of Architecture and Building Systems.

References:

[1] EMPA spin-off Flisom

[2] EU Climate-KIC BTA flagship project

By: Vanessa Bleich
Next year’s Cybathlon will host people with physical disabilities equipped with advanced assistive devices including robotic technologies. The goal of this unique competition is to remove barriers between people with physical disabilities, researchers and the general public and to promote the development of assistive technologies that are useful for daily life. We talked to Robert Riener, the Cybathlon’s main organizer and Professor of Sensory-Motor Systems at ETH.

Robert Riener is the initiator and organizer of the Cybathlon. (Photo: ETH Zurich / Giulia Marthaler)

You are the initiator and main organizer of the Cybathlon. How did the idea for this event come about?
As a researcher, I’m always on the lookout for opportunities to present my research to the general public. A few years ago, I read an article in the newspaper about a man who climbed the stairs at the Willis Tower in Chicago using a motorised prosthetic leg. It inspired me to think about a similar event that could be held here in Switzerland – an event that would extend beyond a single race to include many other disciplines. Through talks with colleagues and employees, I gradually developed the idea further. I also thought increasingly about what exactly we wanted to communicate and achieve with this event.

What do you hope to achieve through the Cybathlon?
Our original idea, which was to present our research findings to a wider public, of course remains a goal that we continue to pursue. But we would also like to raise people’s awareness of the needs of people with physical disabilities and the obstacles they face in everyday life. Unfortunately, many people without disabilities know very little about the challenges faced today by people with physical disabilities. Alongside technical assistance, for example, accessibility is also extremely important. We believe this knowledge, in turn, can break down more barriers.

Besides overcoming reservations about the field, we want to motivate developers to create technologies that provide real support to people in daily life. That is why the races feature everyday obstacles, such as stairs, ramps and doors. We hope Cybathlon’s competitive nature will boost the development of powered assistive technology in the long term. It’s already having a positive impact: new student groups have been formed and research projects have emerged. Both students and researchers are working at full speed on their prototypes.

What are the main difficulties when developing electrically powered devices?
The weight-performance relationship is one of the greatest challenges. For example, if you want to build a wheelchair that climbs stairs, it must be wider for stability reasons. When combined with the additional mechanics and propulsion system, it’s automatically heavier. The same goes for the development of the exoskeleton. The integrated batteries must be very efficient to allow the wearer to move freely and independently throughout the day, but these batteries weigh a lot.

Cybathlon

The Cybathlon will take place on 8 October 2016 at the Swiss Arena in Kloten. People with varying degrees of disability, aided by cutting-edge assistive technology, will participate in the unique competition. A team is comprised by a technology provider and at least one pilot who directs the technological device. As a result, two medals await each winning team at the Cybathlon: one for the parathletes and another for the provider. The technological device that is deployed can either be a product that is already available on the market or a prototype from a research lab.

The competition features six different disciplines:

• Powered leg prosthesis race
• Powered arm prosthesis skills course
• Powered exoskeleton obstacle course
• Powered wheelchair race
• Functional electrical stimulation bike race
• Brain-computer interface virtual race

Robert Riener, head of ETH Zurich’s Sensory-Motor Systems Lab, is the initiator and main organizer of the Cybathlon.

Are there other challenges besides the power supply?
While the performance data for the powered leg prosthesis is already very good, the control is more problematic. The wearer’s intended movements must be correctly conveyed to the leg prosthesis. This means that the prosthesis should automatically detect what the person wants to do, be it standing up, sitting down or climbing stairs. This is less of a problem when it comes to conventional, passive prostheses because the wearer intuitively propels them by moving or swaying.

What is the current state of research in the area of powered assistive technology?
The technology is already quite advanced today in some areas. For example, it is now possible to run quicker with certain leg prostheses than a human with natural legs could. But such prostheses are only helpful for specific movements. You may be able to walk quickly, but not be able to sit down, walk up stairs, or drive a car. Most of the available aids have significant deficits with regards to everyday functions and potential users have therefore failed to embrace them. This is where the idea behind the Cybathlon comes in: systems need to be developed that provide help to people with disabilities where they need it the most – in daily life.

How does the Cybathlon differ from other competitions such as the Paralympics?
People with disabilities can participate and compete in both events. The Paralympics, however, is primarily a sporting competition. Technology remains in the background and the use of motorised wheelchairs or powered prostheses is not permitted. As a result, many people are unable to compete. At the Cybathlon, on the other hand, «pilots» with greater restrictions who primarily direct the technical aids – are also eligible to participate. Although people are at the centre of our event, technology also plays a relatively large role.

The Paralympics are focused on sporting disciplines. In addition to races honouring the athlete who reaches the finish line first, the Cybathlon competition also includes skills and obstacle courses featuring everyday tasks and barriers. It’s not only the time that counts; pilots also receives points for their skills. Just like in classic sporting events, competition drives both the pilots and the technology developers at the Cybathlon. They inspire each other to deliver their best performance.

What has the response been to the planned event up until now?
There’s been a great deal of interest in the event. We have received very positive feedback from the scientific community, the media and well-known Swiss organisations for the disabled. The disability associations share our view that the Cybathlon could contribute to the development of current devices. Some critics, however, argue that these sorts of efforts should be focused exclusively on making buildings and the environment barrier-free. But the world does have barriers and you can’t just make them disappear – there are hills, forest paths and so forth. Researchers are developing technologies so they no longer pose obstacles in the future.

• Novel robots for gait and arm rehabilitation: Interview with Robert Riener
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• Registration now open for Cybathlon 2016

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The Kuka lightweight robot with a mounted stone tool replica in an ETH Zurich lab. (Photo: Fabio Bergamin / ETH Zürich)

By Samuel Schlaefli

With the help of robots, archaeologists may soon be able to compare their findings with data from thousands of experimental reference samples, enabling them to determine tool use in the Stone Age. ETH scientists have developed a robotic system and presented it at the industry fair in Hanover.

Kuka-Roboter

Radu Iovita is an archaeologist. He remembers well his student days, when he spent hours scraping away at animal skins with replicas of stone tools found at archaeological sites – all for a bit of pocket money. Through analysis of wear traces under a microscope, archaeologists seek to determine how the tools were used thousands of years ago. This method, known as ‘use-wear analysis’, is a standard approach in modern experimental archaeology today.

“Manual use-wear analysis is incredibly time consuming, and we are unable to control factors such as the force with which a tool is used or its position,” says Iovita. He has spent the past few years looking for opportunities to conduct controlled experiments and experienced initial success with a system using air guns to run a controlled test on the impact-related fractures of Stone Age spearheads.

Archaeologists and robotics team up

But the archaeologist was looking for ways to examine all tools and their application systematically – as well as being as automated as possible. Iovita, now a researcher at the Monrepos Research Centre (RGZM-Leibniz Research Institute for Archaeology) in Neuwied, Germany, remembered Jonas Buchli, a professor at the Institute for Robotics and Intelligent Systems at ETH Zurich, whom he had met 10 years before at a summer school on complex systems. The ETH professor was impressed from the outset with Iovita’s idea to automate archaeological research through the use of robots to standardise the measurements.

Buchli’s then graduate student Johannes Pfleging equipped replicas of stone tools with sensors. Just as Iovita did during his studies, Pfleging scraped at the animal skins, but with a difference: his movements and the force used were recorded by a computer. In doing so, he found evidence that the sensors provided important data that could be used to reproduce and compare the experiments at a later date. But use-wear analysis still remained time-consuming.

By a stroke of luck, the Kuka robotics company had just announced an Innovation Award that made lightweight robots with force control available for use in innovative research projects. These robots are very light in comparison to their load weight and can adapt the forces used to the determined resistance within milliseconds.

A robotic arm for fully automated analysis

One such Kuka robot has been in Buchli’s laboratory since last December. Pfleging, now a doctoral student, has fixed the grey robotic arm with its seven degrees of freedom on to a wooden table. At the end of the arm is a plastic adapter with a piece of wood in which he glued a replica of a stone tool. As soon as Pfleging starts a computer program he wrote himself, the arm begins to use the stone to scrape a piece of leather fastened to the table. After a few rounds, it bends down and guides the tool under a microscope next to it on the table. An image of the stone, magnified 80 times, appears on Pfleging’s computer, revealing fine abrasions.

“With such a system, we can not only automate the painstaking production of wear traces, but also the analysis of the replica,” explains Buchli. Several robots could work leather, stone or wood with replicas of tools 24 hours a day and run the tool after every 50th movement under the microscope to take images of the surface. Thus, a combination of the data and force of the robotic arm would allow a precise reconstruction of how certain abrasions had been achieved. “Through such analytical data, we could one day create massive databases with all the characteristics of archaeologically relevant information on materials and their wear patterns,” explains Buchli.

Deeper insight into ancient civilisations

Wider comparisons such as these have the potential to accelerate the production of knowledge in archaeology and paleoanthropology. For each archaeologically-recovered stone artifact, the researchers could compare a microscopic image with thousands of records from use-wear experiments from around the world, allowing them to make inferences about how the tool was formerly used.

“In archaeology until now, we have been primarily occupied with the morphology of objects,” says Iovita. “However, it is only when we know what the tools were used for that we can make inferences about culture.” It is also generally assumed today that the prehistoric evolutionary development of humankind can be inferred from how tools were used and the cognitive skills needed to use them. In particular, scientists are still groping in the dark when it comes to the use of tools from the period between 3 million and 50,000 years before present.

Paradigm shift underway

Currently, Iovita is experiencing some opposition from within his own profession. Some believe that manual experiments are closer to the past reality; others find that use-wear analysis in general does not advance archaeological theory. Iovita thinks this is mainly due to the fact that most archaeologists have a humanities background and are not familiar with the world of engineers.

“However, a generational and paradigm shift is currently underway,” he believes. “The interest in automated analysis is growing and more and more archaeologists have access to the relevant technology.”

Iovita has put in an application for the establishment of a trace laboratory at the research centre in Neuwied, where the first use-wear analysis with robots will be conducted in the next two to three years. Buchli and Pfleging have now presented their robotic system to experts as part of the Kuka Innovation Award at the industry fair in Hanover. Next, they will develop a prototype in their laboratory that is better suited to archaeological use and cheaper than conventional lightweight robots with force control.

“In 10 years’ time, robotic analysis will be the standard in archaeology,” predicts Buchli. “For the first time, research results would be truly comparable because the methodology behind it is standardised and the devices properly calibrated.”

This article first appeared on ETHZ News. 

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Matthias Kohler, Balz Halter and Jonas Buchli (Photo: Nicole Bachmann).

By Felix Würsten and Corinne Hodel (Interview).

Digital technologies have already turned many areas of the economy inside out. In this interview with Swiss NCCR Digital Fabrication researchers Matthias Kohler, Balz Halter and Jonas Buchli, we hear how construction is the next sector set to undergo a change, enabling more efficient processes, new materials and more varied houses.

The website of the new National Centre of Competence in Research (NCCR) Digital Fabrication states that: “Digital fabrication promises to revolutionise architecture.” Does architecture need a revolution?

Matthias Kohler: That is less of an objective than an observation: the construction process is still highly conventional. Other sectors of the economy have been profoundly transformed by digital technologies. This raises the question of whether architecture and its downstream construction processes are also set for a change. The NCCR Digital Fabrication addresses this question: what is the added value if components are fully assembled by machines? What conditions need to be fulfilled so that people can work together with robots on building sites? And what effect will this have on drafting, planning and the construction culture?

Yet it must be noted that houses were built by robots in Japan some time ago. Are you reinventing the wheel?

Kohler: It’s true that some initial steps towards automation on building sites were already taken in Japan in the 1990s. There was a boom, but it collapsed suddenly for economic reasons. The idea at the time was to bring serial mass production from factories to building sites. It worked, but this technocratic approach resulted in limits on the architecture and bland buildings. In today’s construction culture, a fitting, “tailor-made” solution for each situation is the objective. The quality of our living environments relies on this. When we take our robots to the building site today, our motivation is quite a different one: we are trying to establish how the processes can be rationalised, but continue to allow tailor-made production at the same time. That’s the actual novelty: every machine-made component can look different, even the individual production steps can be customised to a certain degree. That’s what we’re doing with our robots, for instance: depending on the task, the same robot uses different tools to assemble, process or shape something. This approach results in rational production already for relatively small lot sizes.

Is there actually any demand from developers for individualisation?

Balz Halter: Developers certainly want a more individualised appearance for their buildings. This is also having an impact on architecture: new shapes and materials are being sought. In the construction industry, we abandoned the mass production mentioned earlier because we noticed that this approach keeps resulting in the same buildings. The construction industry is indeed aiming for individualisation, because ultimately it also offers a way to stand out amongst competitors.

What is your motivation as a robotics expert to look at construction processes?

Jonas Buchli: Many sectors of the economy have been turned inside out by digitalisation. This has affected, above all, areas where either data play a key role or where problems can be easily structured. In robotics, however, we now need to take the next step, which is to say that these technologies need to be brought to areas that are less structured, where more flexibility is needed and the machines need to react in a more timely fashion. The construction industry is an interesting starting point for this. A building site is certainly less well-structured than a factory, but still not quite as open as the world of service robots, for instance, which perform activities independently in the household. The potential in the construction industry is huge. But we will only be able to tap it if we solve complex robotics problems. That’s an interesting challenge for me as a researcher.

What has it been like to work with architects?

Buchli: When working with architects, the challenges and possibilities are entirely different than when “only” collaborating with engineers. I am learning an awful lot and am facing an entirely new perspective. What has surprised me is how pragmatic their approach is to using technologies and how target-driven their work is.

What has been implemented to date?

Kohler: We’re currently still at an early stage of research, although some companies have already taken specific steps towards digital fabrication. It will take a great deal of time until the new production processes have become ingrained and until the experiences have been integrated along the entire production chain. In tile and timber construction, we have seen that implementation will take at least six to ten years. When applied across the entire construction industry, these changes will take several decades. What excites me is the question of what we will gain from these technologies in terms of quality in architecture and in the construction processes, and what benefits they will bring for Switzerland.

Halter: In practice, digital fabrication is certainly a known concept today. In timber construction, in particular, a lot is already being done. The fact that these technologies are not yet broadly applied is not so much a matter of possibilities: the problem is that we can only produce digitally if the data are available in a corresponding form. In this area, our industry is simply underdeveloped. There is no integral process from drafting to production through to operation. If we were to start by handling the data correctly during the planning process, implementation would be far easier. We actually have all tools at our disposal already. But our industry is still not able to use these tools.

Why is that?

Halter: First, this has to do with the fact that we still think in a very subsection-specific way. In other words, we don’t understand the building as an overall system. Second, we keep interrupting the planning process because we transfer data from one place to another. And third, the construction industry is organised in a highly commercial and work-sharing manner. The production of a car is a unified procedure; that’s not the case for buildings. But construction is not more complex than car manufacture – we are simply aligned in such a way that it becomes more complicated. That’s why processes are still very antiquated on building sites. But that is also an opportunity, of course, in particular for the design process. What’s important to us is that digital fabrication results in quality improvements and ultimately also generates commercial benefits.

Buchli: The entire development will likely happen in a similar way as in computer technology. When we had the first computers on our desks, processes were hardly productive yet. But there were early adopters, who were thinking ahead. Only now, after many years, are computers really productive for normal users. We will undergo the same development in the construction industry. However, the problem is far more complex here, which is why the time frames will be longer. We won’t be looking back in two or three years saying whether it has worked or not.

Where do you expect to see the first steps?

Buchli: What will likely become established in the near future are transport applications as well as certain precision applications. Today, we can produce structures at a level of precision that a human cannot achieve, at least not within the same period of time and working under the same conditions that robots do. However, if we want to bring these things to building sites, we need to increasingly include information from the building in the planning process. This was a directed process in the past: first plan, then execute. What we need now is to close the circle.

Kohler: The crucial question is, of course, how this vision is implemented. Up to this point, architecture has mainly focused on the mental work. The idea was to develop a sophisticated planning software that integrates everything. This still largely works in planning today. However, where the matter becomes physical, the processes mostly remain conventional. We are now changing our perspective and looking for solutions that can be integrated retroactively, in other words from execution to drafting. I’m convinced that this approach will make it far easier for the construction industry to initiate a sustainable transformation from within.

Do you share this view?

Halter: A lot speaks for this approach. The development is driven strongly by architects who focus on the end product and who work with components and materials that can only be implemented in a digital process. For instance, there are facades that can only be planned and produced on a data-driven basis. It will also be exciting to see what influence 3D printers will have. This is precisely the point: we look at what options we have in production and go back to the draft with this as our vantage point until both ends meet.

Kohler: 3D printing is a very interesting catchword: 3D printers cannot simply be applied to architecture, although it is often presented this way. In principle, additive processes are interesting for us, of course. This has to do with the fact that good architecture is based on the artistic assembling of elements to create rooms that are larger than the machines that build them. This is where 3D printing comes in: how do we find the structuring strategies in architecture that are based on digital technologies, but nevertheless take into account the requirements and economy of architecture? For instance, it makes little sense to print an entire building. Due to the resolution at which the printer works, the construction process takes a very long time and the material is also very expensive. However, if larger construction elements are used, a construction-aligned resolution can be achieved.

Can you elaborate a little on this?

Kohler: I am speaking about new digital material systems, for instance: suddenly it’s possible to handle a building material in an entirely different way thanks to digital technologies. It is very possible that this will result in developmental leaps. We also need to consider the ecological aspects: today, concrete walls are designed in such a way that they withstand the worst load scenario. These walls are built with a straight mould system. This results in about one third of the concrete not actually being needed from a statics perspective. If we use systems that don’t need moulding, there are direct consequences for our handling of material resources. If the construction culture develops in this direction, we will thereby also be able to create added value in this area with the use of digital fabrication. Our research projects allow us to generate knowledge which Swiss companies will be able to use internationally. We would be delighted if the industry were to pick up on these stimuli and if our projects were to result in interesting collaborations.

What effects do these developments have for the people involved in the actual construction process?

Halter: It’s becoming increasing difficult to find the experts required. For that reason, we need to try to support the processes on building sites in terms of information technology in such a way that the required skills are more limited. This objective is also driven by commercial considerations, because the individual worker is becoming increasingly expensive.

What do you think of the roll-out of the new MAS Digital Fabrication programme at ETH Zurich, which is starting for the first time this year?

Halter: No question: we need a programme like this. Because the development we have just been discussing can only happen if we also make changes to education. We need people who can handle these types of technologies. We are consistently initiating innovations, but are also noticing that people are out of their depth in practice, because they are faced with something that they don’t know. A planner doesn’t see why he should do something differently, because he doesn’t get paid more but he does have to take on more risk. If he has no inherent drive to try a different approach for a change, and cannot even know the opportunities, then he simply won’t do it. That’s understandable.

Matthias Kohler is Professor for Architecture and Digital Fabrication at the Architecture Department of ETH Zurich. In 2005 he established the world‘s first robot laboratory for nonstandardised fabrication processes in architecture with Fabio Gramazio and thereby opened up an entirely new field of research.

Jonas Buchli is Professor for Agile Robotics at ETH Zurich. His research focuses on modelbased approaches to controlling robotic locomotion and understanding human locomotion as well as on machine learning and on dynamic service and field robots.

Balz Halter is the owner and chairman of the board of directors of Halter Unternehmungen, which are active in the development, construction and operation of real estate property. He is an ETH graduate civil engineer and lawyer.

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ETH and the university of Zürich receive a 120 million dollar donation from ETH alumnus Hansjörg Wyss. (All photos: ETH Zurich)

ETH Zurich and the University of Zurich are founding a new translational research centre at the interface of medicine, science and engineering: the Wyss Translational Center Zurich. A USD 120 million donation from Dr. h.c. mult. Hansjörg Wyss to the two Zurich universities is making this possible. Through an interdisciplinary approach, the new centre aims to accelerate the development and application of innovative medical therapies and groundbreaking robotic systems.

ETH Zurich and the University of Zurich (UZH) are taking their long-standing partnership to a new level with a new translational research centre. The two universities are founding the Wyss Translational Center Zurich (WTZ) with funds donated by Hansjörg Wyss to the ETH Zurich Foundation. The core idea and motivation behind the initiative is to ensure that knowledge from basic and pre-clinical research can be applied in practice more quickly; in other words, an efficient translation into new medical therapies and innovative products.

The WTZ will initially include two technology platforms – one for regenerative medicine and the other for robotics. The centre will bridge disciplinary and institutional barriers and unite researchers across various disciplines, ranging from technology and medicine through to materials science, stem cell research and robotics. “Basic research in Switzerland is among the best in the world. However, it often takes a long time until the findings can be used to benefit patients. I want to help speed up this transfer with new models of interdisciplinary collaboration”, states Wyss, founder of the medical technology company Synthes Global and chairman of the Wyss Foundation.

The USD 120 million donation is a basic endowment to establish and operate the WTZ for the first seven years. ETH Zurich and UZH will provide personnel and infrastructure in the new centre. On the basis of the two translational technology platforms – regenerative medicine and robotics – the WTZ will commence operations in 2015 with a starting portfolio of four translational projects: Zurich Life Matrix, Zurich Heart/Ventricular Assist Devices, Zurich Liver and Zurich Eye. More groundbreaking transfer projects will be added over time. “The generous donation from ETH alumni Hansjörg Wyss provides a fantastic opportunity to use the many different scientific competences and skills here in Zurich to develop new medical and robotics products,” says ETH President Ralph Eichler. The new research centre will be based at both ETH and the University of Zurich and will be co-directed by professors Roland Siegwart (ETH Zurich) and Simon P. Hoerstrup (UZH). “Combined with the excellent basic research at the University of Zurich and ETH’s proven strength in technology development, the Wyss Translational Center will allow our two institutions to assume a very strong position among the international competition,” states Michael O. Hengartner, rector of the University of Zurich.

From research to product

ETH Alumnus Hansjörg Wyss with the two WTZ Co-Directors , Prof. Roland Siegwart (right) and Prof. Simon P. Hoerstrup.

Within the four starting research projects, the two partner institutions are aiming to develop new medical treatments, prototypes and innovative products over the coming years in order to improve the lives of patients and healthy people. An overview of the objectives of the four research projects:

Zurich Life Matrix: Development of in-vitro engineered human tissues that can regenerate and grow along with the organism. For example, scientists are growing blood vessels and heart valves in laboratories from human cells that can evolve in parallel with the heart (e.g. during the growth stages of a child) and have the capacity for self-repair. Existing solutions are usually of a non-living, prosthetic nature and, as a result, lead to complications that require surgical re-interventions often associated with substantial morbidity and mortality.

Zurich Heart/Ventricular Assist Devices: Development of innovative heart support pumps (ventricular assist devices). Many people today suffer from life-threatening heart problems. Artificial heart pumps support the diseased failing heart allowing patients to enjoy a good quality of life in the long term despite the lack of suitable donor hearts. However, there is still much room for improvement related to the biocompatibility, control, ergonomics and size of existing heart support pumps.

Zurich Liver: Development of innovative extra-corporeal perfusion systems. This will allow, for instance, a part of a patient’s liver to be grown outside the body and be transplanted back into the patient. This process would enable patients with serious liver diseases such as cancer to generate their own donor material and significantly decrease the demand for donor organs while increasing patient safety at the same time. The process could then be applied to allogenic transplantations and pave the way for one donor liver benefiting more than one patient.

Zurich Eye: Development of a camera-based positioning system that automatically creates maps of the environment and enables precise positioning. This system is intended to help autonomous vehicles and aircrafts navigate independently in disaster operations, transport and agriculture, and support people in various tasks.

This article originally appeared on ETH News.

The cardiologist sits in the control room next to the operating theatre and uses a joystick to steer a catheter through the patient’s blood vessel into the heart’s chambers to treat the cardiac arrhythmia precisely. With this robot-controlled surgical system, Phocus, the ETH spin-off Aeon Scientific won over a panel of 15 judges at this year’s Swiss Technology Award, presented last Thursday at the Swiss Innovation Forum in Basel. The company from Schlieren won the prize in the Start-up category. “We are delighted that our work has been recognised and appreciated,” said Dominik Bell, CEO of Aeon Scientific. “The award will help us market our product and find new investors and staff.”

Precise guidance with magnetic fields

Aeon Scientific originated from ETH Zurich’s Institute of Robotics and Intelligent Systems (IRIS). The start-up’s work focuses on making conventional surgical procedures safer and simpler. They develop devices that use magnetic fields to steer instruments remotely with millimetre precision inside the human body. The foundations were laid by the team of ETH professor Bradley Nelson, a co-founder of Aeon Scientific. The scientists began their research into a magnet-controlled surgical system at IRIS in 2003, before establishing the spin-off in 2010. The first Phocus system will be put into operation in January 2015 in Zurich.

Bell believes this steering system based on magnetic fields could also be used in other areas of medicine. He is hoping that the company can establish a number of other robot-controlled medical treatments, not just for cardiology. He says that magnetic forces could be used to steer a wide variety of instruments such as catheters, guidewires and endoscopes, or even capsules containing active ingredients, directly to the source of an illness within the body.

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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

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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

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