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Robots Podcast #180: Soft Robotics Toolkit, with Donal Holland

Harvard Biodesign Lab         

interview by
April 17, 2015
image: Soft Robotics Toolkit
image: Soft Robotics Toolkit

In this podcast, Ron Vanderkley speaks to Donal Holland of Harvard University about his team’s work on the Soft Robotics Toolkit.

Soft Robotics is a class of elastically soft, versatile, and biologically inspired machines represents an exciting and highly interdisciplinary paradigm in engineering that could revolutionize the role of robotics in healthcare, field exploration, and cooperative human assistance.

The Soft Robotics Toolkit is a collection of shared resources to support the design, fabrication, modelling, characterization, and control of soft robotic devices. The toolkit was developed as part of educational research being undertaken in the Harvard Biodesign Lab. The ultimate aim of the toolkit is to advance the field of soft robotics by allowing designers and researchers to build upon each other’s work. The web site contains the open source fluidic control board, detailed design for wide range soft robotic components (including actuators and sensors).

The growing popularity of site is now bringing in hobbyist and makers alike. The Soft Robotics Toolkit team has announced two competitions intended to reward students, researchers, makers, and designers of all levels for their contributions to the field of soft robotics.


Donal Holland


Donal Holland is a visiting Lecturer in Engineering Sciences at Harvard School of Engineering and Applied Sciences Demographic info Ireland | Mechanical or Industrial Engineering. He was a passed PhD Student at Trinity College Dublin, Visiting Fellow at Harvard School of Engineering and Applied Sciences, Research Assistant at Treocht Ltd.





Ron Vanderkley:  Welcome to the podcast. Can I get you to introduce yourself?

Donal Holland:  My name is Donal Holland and I’m a visiting lecturer at Harvard School of Engineering and Applied Sciences. I’m a mechanical engineer, and I’m one of the developers of the Soft Robotics Toolkit.

Ron Vanderkley:  Can you explain what soft robotics is?

Donal Holland:  When we say soft robotics, we mean robotic systems that are composed partially or entirely from soft, low modulus materials. In plain language this means materials that are very stretchy or those that are flexible or bendy. This is still quite a broad definition, and in our work we mostly focus on actuators and sensors that are composed from fabrics or elastomers, like silicone. That’s what soft robotics means for us.

Ron Vanderkley:  Can you explain what the Soft Robotics Toolkit is?

Donal Holland:  The Soft Robotics Toolkit is an online connection of resources that are related to soft robotics research and development. We intended it to be an intellectual toolkit rather than a physical collection of parts or tools. The toolkit is a website that describes the design, fabrication, modeling and testing of soft robotic components. We currently have documentation for three categories of components on the website, covering actuators, sensors and control hardware. And for each component, the documentation discusses the design of the component, for example, by giving an overview of how it works, discussing the effect of different parameters on its performance and, where appropriate, we provide tutorials on modeling the component in CAD software. It then talks about fabrication in step-by-step tutorials for how to build this yourself, including building materials and where you can order the materials required.

Depending on the component, we also talk about the kind of research that’s been done on it. For example, how we model this mathematically or numerically, or how we carry out testing to understand its performance. It’s said to be very self-contained and to give an overview of how it’s designed, how it’s built, and how it’s used.

We don’t really talk about how we then combine them into full systems; we leave that open ended to the user. We want to see where people will go themselves. But we do provide some case studies of what other people have done using this component.

Ron Vanderkley:  So basically the toolkit has helped students kick start in the field of soft robotics, eliminating the need to join all the dots together?

Donal Holland:  Exactly. We want to help people avoid reinventing the wheel and build upon each other’s work so that we can move soft robotics forward at a faster pace.

Ron Vanderkley:  As you pointed out, it’s being developed as an academic tool. Has the up tide meant that now there are a whole bunch of other types of users that are very interested in developing their interest in soft robotics?

Donal Holland:  That’s absolutely the case. Originally our goal for the toolkit was for it to be an educational resource for use in our classrooms. We teach some design courses and we want to develop resources that could be useful for our students. So we carried out research to understand what our students’ learning needs were, and then we developed an initial version of the documentation and tested it with a range of undergraduate students just to ensure that it was clear enough that they could understand it.

Next we used the results from these tests to improve the documentation, and then we used it in our own design courses for two years. We usee the feedback from these tests and from our own students to further improve the website, and then in September 2014 we launched it to the public.

While our initial goal was to develop a classroom resource, we also realized along the way that the website could serve a broader educational purpose. For example, soft robotics is a very multi-disciplinary field. We have chemists, mechanical engineers, biologists, electronic and computer engineers all coming together, bringing their own expertise together to develop new systems. The toolkit is a way for these different disciplines to share their knowledge and educate each other so that the field can move along at a faster pace. We’ve also had a lot of interest from high school and middle school teachers and students who would like to use it in their classrooms. There’s a big and active hobbyist community around robotics and Makers in general, and we’ve had a lot of interest from people in those communities as well.

Since launching it’s become a lot broader than we originally intended it, and we’re very excited to see where it goes next.

Ron Vanderkley:  As you pointed out, it’s essentially a list of components etc. Has anyone suggested turning it into something someone can actually purchase? Or is it left to the individuals for source material?

Donal Holland:  At the moment it’s very much left to the individual, but we have had a lot of people suggest or ask if they can buy it. It’s not something we’ve done yet but we’d definitely be open to bringing the components together to make it easier for users in the future. I think one of the big challenges, especially when you’re doing this internationally, is that what might be easy to obtain in one country is almost impossible in another – that’s something that we’re really running up against when we’re working with people around the world.

Ron Vanderkley: I was wondering about how to come up with some of the components in this part of the world …

Donal Holland: I had that experience myself when I lived in Europe, and there’s a lot of really good open source, open design projects out … there but a lot of the time they are based in the US and trying to find the same components in Europe is very difficult. I understand the frustration that people have when they’re trying to do that, so as an interim step we’re very keen to work with people in other countries to find local suppliers that could do equivalent parts. For example, we’re working with some educators in Brazil who are sourcing parts in their own country that we will then put up on the website. We are very open if anyone in any part of the world is interested in contributing lists of local suppliers – we’d love to host that on the website to make it easier for people to be involved.

Ron Vanderkley:  What were the challenges in creating the kit?

Donal Holland:  One of the big difficulties with sharing this type of information – where you’re trying to take expert’s knowledge and share it with other people – is the problem of tacit knowledge. People who are very familiar with a particular field or technology or fabrication method typically have a lot of knowledge that it’s very difficult to make explicit. They often don’t know that they know themselves, if that makes sense. And so it can be difficult for experts to document their knowledge in a way that’s sufficiently clear for non-experts to understand.

Put in another way, an expert has forgotten what it’s like to not be an expert, so it’s difficult for them to educate other people sometimes. Our way of getting around this has been to observe interactions between students and experts and to record a knowledge that is shared. The great thing about these interactions is that the experts have to try to explain their knowledge to a beginner and the beginner is able to ask questions about anything they don’t understand.

That’s really useful for our purposes, and it’s how we overcame that difficulty when we were creating the tool kit.

The next big difficulty that we have is for this to really be useful and sustainable … We need to encourage experts from all around the world to share their knowledge. We want this to be much bigger than ourselves and we see this as a community resource – not our own website. We’re trying to figure out a way to incentivize people to be involved to contribute their knowledge and to stay involved.

Ron Vanderkley:  Are there example projects that are being created that students can actually take a look at, or get inspired from?

Donal Holland:  The toolkit focuses very much on the basic components, which can then be combined to create new devices and systems. By focusing on the fundamental building blocks and keeping it open ended, we hope that more people can take it places that we never would have thought of. To encourage this we’re currently holding a soft robotics design competition, where we’re asking website users, including students and hobbyists, to create something using materials on the website and then to document their designs. Then in July we’ll announce the best designs, share them on the website, and the designers will receive cash prizes. The documented designs will act as examples of what people can do with the toolkits that students can learn from.

Ron Vanderkley:  What is the future of the Soft Robotics Toolkit? Has someone set a timeline? Is it just going to run almost by itself?

Donal Holland:  Ideally, we would like it to get to a stage where it could run by itself. I think right now we’re still very much figuring out what the future of the toolkit is. It’s only really been a few months since we launched to the public and we’re still basically collecting feedback from people to figure out what would be most useful for the soft robotics community, what would be most useful for the maker community, and of course what would be most useful for students. We’ll use that feedback to try and figure out where we go next. But I do think a big part of it is trying to make it more of a community resource and people who are outside the original development team taking over responsibility for parts of the website and making it their own.

Ron Vanderkley:  What is the future soft robotics? Where will it go? Specifically, I noticed that the whole kit is dependent on quite a large environment. Has anyone looked at miniaturizing it and tethering it from the rig?

Donal Holland:  That’s a great question.

In terms of the future of soft robotics, I think there’s a lot of excitement about the field … so I’m really interested to see what the near future is going to hold. Our main interest is in medical applications – most of the research we do is related to the medical applications of soft robotics – and there are already some very nice soft robotic medical devices on the market. That’s one very interesting area that’s definitely going to continue over the next few years. Another area that’s receiving a lot of attention is industrial applications, so in particular end effectors for grasping will definitely continue to grow. In both these situations I think it’s okay to be tethered. For example, if you’re on an industrial robot with a large robotic arm, I think it’s okay to have a fairly large pump that you can be tethered to. You don’t need to be too mobile.

In terms of research applications, a very exciting area right now is biomimetic robotics. There’s a lot of really cool work being done on robots that imitates biological forms – especially animals. One of the reasons this is so interesting is that, on the one hand, roboticists are learning from biologists and are making better robotic systems as a result. And on the other hand, I think robotics research can potentially lead to a better understanding of biological systems. But this is an area where making things untethered becomes very important … for example people building autonomous swimming robots. There’s some pretty good work being done in Daniela Rus’ group at MIT in this area; they have completely un-tethered fish robots that can swim around without being attached to a big rig. This is the area where untethered systems are really going to come from, and there’s going to be some really interesting research done in the next few years.

Ron Vanderkley:  I noticed that they had an example of a combustion system that uses gases to generate thrust. Is that just another up and coming example of where soft robotics can go?

Donal Holland:  This is an area I haven’t been involved with really. The documentation for that project came from ETH, which is great – we are delighted to have contributions coming from outside, and that was our first contribution. There is some work being done at Harvard in that area. I think it’s really interesting because in typical pneumatic systems, the actuation time is quite slow and in our applications, which are often medical, we’re not really bothered because speed isn’t that important – what’s more important is that you’re not doing any damage.

But for biomimetic forms, if you want to have a robot that can jump for example, then you want to be able to do much faster actuation … and that’s where combustion becomes really, really interesting. Again, I think that’s where the biomimetic robotics is really pushing the boundaries of soft robotics actuations. It’s definitely something to keep an eye on and see what’s going to come out that area in the next few years.

Ron Vanderkley:  Should we be looking at the Harvard lab for their next steps, or are there other organizations also moving as rapidly as Harvard?

Donal Holland:  I think there are a lot of groups doing really good stuff around the US, almost too many to list. There’s a lot of really great work at MIT, Carnegie Mellon, at Cornell, a lot of interesting wearable stuff going on at Stanford, in ASU. Around Europe there’s of course the RoboSoft CA that are coordinating a lot of the soft robotics research in Europe and further afield. So it’s hard to try and list off the groups here because there’s just so many it’s really grown in the last few years.

Ten years ago it was a very small handful of researchers mostly in Japan – I should mention there’s a lot of really great work going on in Japan as well. But ten years ago it was mostly a small number of Japanese research groups and now suddenly it’s very much exploded and all over the world there are so many people doing really great work. I work in the bio design lab at Harvard with Professor Connor Walsh, and in terms of our immediate interest, I think wearable robotics is the area that we’re really interested in, but there are a lot of other groups at Harvard as well who are doing really good research, ranging from biomimetic systems to different types of medical devices.

Ron Vanderkley:  Thank you Dolan for your time. We’re excited to see what happens with the competition!

Donal Holland:  Thank you very much for having me. We’d be delighted to hear from any of your listeners with any feedback or thoughts on the toolkit.

All audio interviews are transcribed and edited for clarity. However, we can not assume any responsibility for their accuracy.

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