When we think of robots, we likely think of metal or plastic parts, synthetic actuators and/or sensors. One lab is aiming to change all that by using muscular and neurologic tissues instead, with the goal of creating completely organic, sustainable, and programmable biorobots. The lab is called the Biohybrid and Organic Robotics Group (B.O.R.G) and is led by Victoria Webster-Wood, Assistant Professor of Mechanical Engineering at Carnegie Mellon University. She joins us today to discuss her research in this exciting field.
The benefits of biorobots are numerous. Traditional robots are fragile – if a robot made of traditional materials tips over, it could easily break or have one of its components dislodged. If we or another animal fall over, our pride may be wounded, but the fat and muscle on our body often prevents our bodies from being seriously damaged. Having biorobots made from these materials could allow biorobots to exist in the natural world in a new and safer way. Robots could exist in ecosystems, assisting humans with search and rescue missions, environmental monitoring, and biomedical research. Tune in to find out how exactly these robots are designed, maintained, and when we might expect to see them out in the world.
For more information, please visit www.engineering.cmu.edu/borg.
Richard Jacobs: Hello. This is Richard Jacobs with the future tech and future tech health podcast. I have Victoria Webster-Wood. She’s an assistant professor of mechanical engineering. So with a courtesy appointment in biomedical engineering at Carnegie Mellon University. And her research is interesting, so I’ll let her describe it. But Vicki first, thanks for coming to the podcast. How are you doing?
Victoria Webster: Hi Richard. Thanks for having me. I’m doing well.
Richard Jacobs: Yeah, it looks like you’re working on the integration of organic material into robots, essentially making a, I guess a Cyborg S type of arrangement, but how would you describe it? What are you working on?
Victoria Webster: Yeah, so my lab is the biohybrid inorganic robotics group here at Carnegie Mellon. And what we’re really doing is we’re trying to create an engineering science for the use of renewable organic materials in robotics and other technology platforms. And we’re really driven by this fundamental question, how you capture these amazing capabilities that we see in animals in safe, robust, autonomous robots. And the opportunity we’re exploring is the possibility of actually using living organic material as components of the robot, such as muscle tissue for actuators or neurons for controllers.
Richard Jacobs: Okay. So what kind of organic material, I use a lot of questions to ask, which ones are the most easily assimilate able or which ones make sense to you right now? Which parts are you trying to assimilate?
Victoria Webster: So we really started by originally focusing on muscle as an actuator. When we started this work, I came to it from a background in a bio-inspired robot where we were building the devices out of metals and plastics and traditional materials. But we were always trying to make our robots get around better in, in complex changing environment and failing to really capture what we saw in the animals and one reason we thought that we might be falling short was the actuators. So animals are inherently squishy, right? Our muscle is squishy. If we fall down, we get back up and robotic actuators aren’t as squishy and so we started with muscle and moving forward from that now we’re also looking at, how we can use neurons as controllers and sensory cells as sensitive biosensors in these robots?
Richard Jacobs: Well, focusing on muscles first, what is an actuator and what’s a simple definition of one?
Victoria Webster: Yeah, so an actuator is a device that basically let something move. So common actuators in traditional robots would be things like motors that might be turning the wheels of a robot or moving an arm joint of the robot. There’s also actuators that are based on air or fluid pressure that kind of expand these balloons to move components of the robot. And in our robot, rather than using these mechanical materials, we’re actually growing living muscle tissue and then stimulating it so that it can track. And in that way, we’re able to move the legs of our robots.
Richard Jacobs: Okay. So what kinds of things can happen to a mechanical actuator? Like the robot falls down and the actuator gets broken and how does it work in the human body, for instance, differently or in an animal?
Victoria Webster: The kind of traditional robotic actuators, a lot of them are inherently rigid. They’re hard. And so if you think about the big industrial robot that we see in manufacturing, if one of those runs into a person or a piece of equipment, it’s going to do a lot of damage because as you say, it really doesn’t have any give. Whereas in an animal, because we are able to move through the system of muscles pulling on different parts of our bone and rotating our joints, the muscles act kind of like spring. And so if our arm runs into something we can kind of adjust to that contact and not necessarily damage what we’ve bumped into or damage ourselves because we’ve got that springiness to our muscles.
Richard Jacobs: So can I imagine like there’s one type of an actuator or let’s say a piston?
Victoria Webster: Yeah, Piston would be a type of actuator.
Richard Jacobs: Okay. Cause that makes sense to me. Cause then if I dent a piston, it can’t move through its range of motion properly or it’ll move all over the place. Or if I push against the side of a piston, it may not again move properly. It may move off at an angle, but an animal, let’s say, you know, there’s a piston S type thing and it gets bumped, that won’t dent, you know, the animal’s piston-type actuator and it can still function. No problem. Right?
Victoria Webster: Exactly. So in the piston example, yes if you bumped the side of the Piston then you make a dent, your piston may not be able to move through its full range of motion. If you think about your bicep as kind of a piston-like actuator. If you bump your bicep on the edge of a door and you may have a bruise but your muscles still going to work and it’s going to be able to self-repair, which is an interesting ability that we see in the living tissue that we just don’t have in traditional actuators for robots.
Richard Jacobs: You know, I could see again with the piston example, for a robot, you can make it out of high-grade steel, so the piston super strong, but in an animal, the good thing is that’s resistant to bumps or dents, that kind of thing. But how does it get hard enough to act like a piston, for instance? How does the muscle harden up to do its job? You know, in a useful way.
Victoria Webster: So in our research, we really aren’t necessarily trying to achieve all of the capabilities that you can get with these engineered mechanical actuators in that, for the types of applications we’re targeting, we really want to have the adaptability and flexibility that animals have. And animals really don’t have these hard actuators and it’s actually an important part of how they’re able to adapt to complex changing environments. There are some excellent videos on the Internet of these mountain goats hopping all around these sheer cliffs spaces that look like there’s nowhere to climb. But because they have this behavioral flexibility and these compliant actuators, they can navigate in that environment that would be extremely difficult for traditional robots to handle.
Richard Jacobs: I would guess you’re starting with a robot actuator and you’re trying to make it, I mean, one way to make it softer in my mind is like shielded, you know, it’s softer material. But is there a way to inherently taking the actual material that does the actuation and make it more flexible aesthetic to resist damage or abrasion or shearing or whatever other forces that impact them?
Victoria Webster: So there is research in soft robotics that does look at using softer engineered materials to build actuators. So, using polymers to build the actuator. And while that is one approach, those approaches still rely on synthetic materials. And one of our real big targets in my research program is to really create green renewable materials for robotics, essentially materials that we can farm to build our robots. And so we really want to use biocompatible biodegradable materials. So instead what we view is rather than starting with the robot actuators, rather than starting with the system and trying to make it soft, we are building soft actuators more from the ground up by growing cells to form functional tissues that we can then get to contract.
Richard Jacobs: So the whole actuator itself will be composed of cells that you can put a current through and cause them to act as an actuator.
Victoria Webster: Exactly and we’ve really approached this in two ways. We have one technique that we use where we grow individual cells into muscle tissues and then stimulate them electrically. But we’ve also developed a method where we can harvest neural muscular tissue circuits from a sea slug, which are very robust marine animals. And with that, we’re able to actually isolate very robust, structurally functional, biohybrid actuators that we can then integrate with our robot so that we can build robots out of materials that perhaps are native to an ecosystem.
Richard Jacobs: Alright. What makes the sea slugs robust? Like what kind of activities would they do and what kind of insults do they observe? And that they recover from?
Victoria Webster: The Sea Slug I work with are Aplysia Californica and they live in the intertidal region off of the southern coast of California. So in this environment, they actually live in these tide pools and among the rocks and in that environment, the tide will go in and out and they’ll experience these turbulent water conditions. When the tide is out, there may be a limited amount of water in their pool. The Sun may be down and the temperature of the water may change significantly or it may rain and change the salt content of the water. And these animals are able to adapt to all of these changes, which we see actually translates to these neuromuscular tissue circuits. So the robots that we’re able to build out of these materials are capable of functioning over a very wide range of temperatures that many mammals would not really be able to accommodate as well.
Richard Jacobs: Yeah, I see what you mean. They can be salty-dry, salty- wet, cold-wet, non-salty, hot-salty and that would dramatically change how they would have to act. Plus you’re being sheared all the time by the tide, probably have sand particles on them. It makes sense. Interesting.
Victoria Webster: Yeah. And one of the applications that I’m really excited about with these robots that we’re working towards is the idea of being able to create form of completely biodegradable robots for environmental monitoring and aquatic ecosystems where you could use organic tissues from an aquatic animal native to an ecosystem to build the robot so that if the robot breaks down or interact with native sea life, they’re essentially just-food. And so you can do minimum damage to the environment. Well, providing a lot of these monitoring tasks that we really need devices able to do.
Richard Jacobs: Well that’s interesting. So the robot-like totally fails. It’ll literally just become food for all the neighboring creatures and will not impact the environment in a bad way at all.
Victoria Webster: That’s one of our goals.
Richard Jacobs: That’s pretty interesting. Do you conceive all this or was there another scientist that can see that this and you’re just doing the implementation part of it?
Victoria Webster: So I really got started in this area of biohybrid robotics, back when I was a Ph.D. student at Case Western Reserve University. And in that role, I had a really unique opportunity to expand on the research that I was doing in the biologically inspired robotics lab to look at kind of the first step towards this goal. In the beginning, we were just looking at how we can grow muscle cells into functional tissue to actuate our robots and when we started that, we were actually using muscle cells from chicken eggs and we were able to build robots that could crawl around, but they had a lot of restrictions. They needed really specific temperatures, ph’s and osmotic conditions to function. And that’s really what led to this idea of using the sea slugs? Can we use materials from the sea slugs to build these robots? And so, over the course of my Ph.D., we developed some initial prototypes in this. And now this past year, last August, I started at Carnegie Mellon University and established my own group, which is continuing to move this research forward.
Richard Jacobs: Interesting. So what are some of the specific use cases you want for these sea slug gasket vessels?
Victoria Webster: So we’re really looking at targeting applications where you may want a form of relatively low-cost robotic devices that are not going to damage the environment and there’s a lot of hazards in the aquatic ecosystems all around the world that we really do need platforms to keep a better eye on. For example, as a result of agricultural runoff, we’re seeing increases in toxic algae blooms, which if those blooms get into the actual coastline, can contaminate water supplies for local communities and if we had robotic devices that could be deployed out into those bodies of water and essentially warn the communities of the incoming blooms, there could be some definite advantages to that. Additionally, we’re looking at how we could locate sources of chemical hazard in coastal marine environments. So for example, if you have a leaking pipeline, how can you detect that earlier and know to deploy teams to fix it.
Richard Jacobs: You know, it’s one thing that occurred to me is you said when the robot breaks down, it becomes food. Any problems of it being food before it breaks down? Like what if a fish try to eat it while it’s operating and peck away at it because it’s essentially food to them or is that not a concern?
Victoria Webster: Right. So I think that almost certainly is definitely a concern. We’ve talked about as a small research community on this, a number of strategies to kind of handle that. One strategy is if we can decrease the cost of these devices sufficiently by being able to really just farm materials for them then we could release large enough swarms that if a couple of them get eaten, the swarm still function. Another possibility is again, taking inspiration from actual organisms and thinking about how we can include defense mechanisms. For example, the sea slugs when they feel threatened to produce a plume of this brilliant violet ink to essentially distract their predators so that they can getaway. Is there something like that that can do that? It’s still biocompatible as a defense mechanism but could deter predators from eating the robot.
Richard Jacobs: It’s weird, like you almost try to make a life for them, but not quite interesting. There is a lot of considerations. So what have you seen so far? Is it super expensive to try to make these robots or to the costs look like they’re not going to be too terrible?
Victoria Webster: Right now it’s really depended on the approach for robots where we’re trying to grow tissues from the single-cell level and kind of build our own systems. We do face all of the same limitations as kind of more biomedical Tissue Engineering Research, which can require pricier re reagents at this point. We are looking at how we can use lower-cost materials as the platform for the robot and then with the sea slug approach, what we’re looking at is, can we farm the sea slugs and basically have a mechanism by which we are able to harvest cells or tissues from sea at different points in their development to get the behavior that we want. And that approach at this point looks like it could very well provide a low-cost approach to these types of robots relatively compared to other approaches in robotics.
Richard Jacobs: Well, how do you empower these robots? What is the material come from? Like what are they used to function
Victoria Webster: Right now the field is very young and so these robots are, I believe, almost exclusively functioning in research labs and as such, most of them are running around in Petri dishes, filled with a liquid solution that contains the right salt balances and nutrients such as glucose. And then the tissue is actually able to extract energy directly from that liquid environment so they don’t even really need batteries to function and one challenge that that does mean moving forward that we’re looking at is how do we package these devices, right? Essentially they’re going to need skins and basically some sort of internal nutrient supply or a method by which they can extract more energy from the environment. And these are all very interesting research challenges the field’s going to have to address moving forward.
Richard Jacobs: Can you power these robots by using the salts that are in the ocean? Most creatures, it seems like they need to eat some of their organisms or plants in order to get that denser energy in order to function. They don’t just live off of seawater, but perhaps you could make these things live off the seawater.
Victoria Webster: Right. So with the living tissue, we would certainly still need a source of energy, some sort of sugar probably. We use glucose. But, that’s one of the things that actual living organisms are extracting from their food supply is the carbohydrates and the proteins that they need to function. So we would have to, for a long-term mission, have a mechanism that lets our robots get those nutrients from the environment and it’s certainly something that we have not solved yet.
Richard Jacobs: Well, maybe that’s what the constraint on the life of the robot. You know, maybe you package a dead shrimp into with the robot and they’d eat off that shrimp for a week and a half. And then that’s it. And then the shrimp has been consumed. Now the robot itself becomes food. Maybe that’s the way to do it. Onboard food. It keeps it alive for a certain period of time.
Victoria Webster: Yeah. I think packaging the right energy supply with them will be an important first step. And for limited missions that can absolutely probably cover it and I do think one thing that as a research field that we’re trying to be aware of as we develop these things is, in using these organic materials we really don’t want to create fully functioning organisms that could end up being invasive to the environment where we’re releasing them to. And so we really do want to have programmed lifetimes for the devices and the ability to control and collect these devices as appropriate so that we are not introducing essentially invasive species into the areas we’re trying to monitor.
Richard Jacobs: Okay. Yes. I know a project like this just seems that it can go so many different ways. Like how do you manage the complexity of it? What have you had to do?
Victoria Webster: Absolutely. I think that one of the challenges that are a very fun part of being a new professor is taking, which is all of these fun things we’re going to look at first. And so far we’ve tried to really take an approach where we are studying these organisms to identify bio-inspired design principles that could be applied to our biohybrid robots, but also have applications in a more traditional robot. And then in the near term, we’re really looking at establishing these paradigms that will let us build organic actuators or organic controllers or organic sensors. And as we are able to make advances in each of those areas that will give us the platforms and technologies that we need to really integrate them into complete robotic systems in the future.
Richard Jacobs: Okay. So what would be like a happy result for you? You know, the next three to five years?
Victoria Webster: So I think that what we’re really trying to establish now is this paradigm of harvesting materials from a renewable organisms and build a robot that capable of performing a targeted task, with organic actuation, sensing and control and so for that, we’re really starting with these sea floods based robots where we’re looking at building platforms that are able to locate chemical forces or light forces and aquatic environments using the organic sensor packages and actuators that we’re developing. So I think in three to five years are targeted certainly to have these devices capable of performing these tasks and ideally packaged such that we can begin doing testing in real-world environments.
Richard Jacobs: Okay. Very good. So what’s the best way for people to get in touch, see what the lab’s doing and ask questions?
Victoria Webster: If people are interested in learning more, they can certainly check out our lab website at engineering.cmu.edu/borg or follow us on Twitter @The_CMU_BORG.
Richard Jacobs: Okay. Well very good. Victoria thanks for coming on the podcast. I really appreciate it.
Victoria Webster: Thank you for having me.
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