Itai Cohen on building microrobots, collaborating across disciplines and taming fear

Academia can be a very siloed place, but Itai Cohen, professor of physics in the College of Arts and Sciences, has managed to work on an incredibly eclectic range of projects, from studying the neuroscience behind insect flight, to making origami-like solar materials that wrap buildings, to creating tiny diffractive microrobots that can probe the microscopic world. He reflects on where his diverse interests and collaborations have led him, and the role that fear played in the evolution of his scientific trajectory.
Read about the tiniest walking robot and its micro-measurements.

Transcript

David Nutt  00:05

Welcome to the Cornell Chronicle podcast, where we speak with the people behind our latest headlines about how they came to make their discoveries and what their discoveries mean for the world. Today we're talking with Itai Cohen, professor of physics in the College of Arts and Sciences, whose research spans a variety of interests and scales, from the properties of complex fluids to the mechanics of biological tissues to locomotor behavior of individual insects and the collective motion of crowds. He also makes origami inspired micro-scale structures and robots - tiny, tiny robots. Cohen and his collaborators have created a range of micro-robotic systems that can fold into 3D shapes, actuate their limbs, pump water via artificial cilia and walk autonomously. His most recent paper combines microscopic robots with optical technologies to develop untethered, magnetically controlled diffractive microbots that are small enough to diffract visible light and flexible enough to undergo complex reconfigurations. These diffractive robots could provide novel ways to probe the microscopic world and to control light. So Itai, connect the dots for me here. Where did your research interests begin, and how have they expanded or changed over time? How does someone trained in fluid dynamics get to microrobots?

Itai Cohen  01:30

Yeah, that's a great question. I think that the evolution in my scientific trajectory has to do a lot with fear. So as a young person, I was incredibly curious about the world, and I really credit this to my mom, who introduced me to just different communities - artists, scientists, philosophers - and showed me that in each of these worlds, there could be something fascinating to get absorbed in. And so as a young man, I was, again, just sort of smitten with all of the possibilities that were out there. But as I grew up and anxiety sort of takes hold, you sort of start to think about what you need to do in order to succeed and make sure that you don't fail. And the making sure you don't fail part sort of starts to dominate. I had a little bit of a crisis after my sabbatical. Everyone thinks of sabbaticals as sort of the best time in a professor's life, because that's when you've worked seven years or six years of your life. You're burning the midnight oil, getting all the papers out, and finally, you have a year's worth of vacation. But what happens to people like me is that that year ends up being one of great rumination and you start thinking about what the heck you're doing with your life, and realizing that life is limited, that you only have a few more of these rounds to go before your time is up. So one of the things that came out of that moment of crisis was this conversation, this set of conversations that I had with my colleague, Paul McEuen, where we really started to think about what we could do to address this very famous problem that was set up by Richard Feynman in his famous lecture "There's Plenty of Room at the Bottom." And the basic problem, or the sort of prophecies that Richard Feynman gave us, were that in the coming decades, electronics would be miniaturized, and 50 years of Moore's Law have led to massive miniaturization of electronics. We can now build circuits where the line widths of individual wires are three nanometers. So it really is unbelievable how much information and circuitry you can condense into this small space. Now in that same lecture, Richard Feynman prophesizes the miniaturization of machines. And what I would say is that the last decade has really spurred this massive interest in trying to control and build and master machinery at the micro scale. And this is really where Paul and I had some of our ideas of where to sort of go with this work. And what we realized was, like, the main epiphany was that, you know, the brains of these machines that's already done 50 years of Moore's Law, right? We know how to make these brains really, really tiny. What was missing were the ways that we could actually move things at the micro scale. So how do you actuate? And the only thing, the only technology we had available, was things like MEMS technology, which, even though the word micro is in MEMS, those devices can only bend to millimeter radii of curvature. And if we were going to build microscopic machines, we needed to be able to fold and bend things to a micron radii of curvature. So that's 1,000 times smaller. And this is really where our journey began. And once we figured out how to make these tiny actuators, these microscopic actuators, this entire world opened up.

David Nutt  05:22

And what are like the, what are the big challenges with, with creating those movements? Is it about the material? Is it about? Well, what is it about?

Itai Cohen  05:32

Yeah, no, no. So it's, it's a materials problem, all right, and that's where, that's where all of this started, was we wanted to make actuators, and the sort of naive way to do it is to basically make a bimorph. A bimorph is a material that's made out of two layers, one layer that can expand relative to the other. And the idea is that if you sandwich these layers together, then the expanding layer that's going to sort of make the combined structure  stretch on one side, and it's going to end up bending All right. And the real trick is that if you want to make something bend on the micron scale, those bimorphs need to be nanometer thin. So we went to work. Our post-doc Marc Miskin, now at the University of Pennsylvania, basically spent his time during the post doc at the nano fabrication facility here at Cornell. And this is one of the big unfair advantages that we have as researchers in a university setting, is that we have access to a world-class research facility for fabrication of nano scale devices. It's probably the best in the country. So Marc spent almost a couple years just looking through and building nanometer thin bimorphs Out of all sorts of different materials that we could try to actuate chemically or actuate with acid base reactions, actuate electronically. And he came up with a set of structures that could do it. Our first one was actuated using a chemical actuation process. So the actuator was built out of two nanometers of glass bonded to one graphene layer. So it was the world's thinnest bimorph. And when we expose the glass to acid, the hydronium - so this is hydrogen with a water molecule attached to it - would enter and replace the sodium. And since hydronium ions are larger than sodium, that would end up stretching the glass. The graphene would stay the same length, and so the actuator would bend, right. So that was the first one, and then we started figuring out how to do this more reproducibly. And the real big breakthrough that came was when we could do it electrochemically. So that means that now we can use electricity to drive the bending. That occurred when Marc made a platinum actuator. So now we have platinum on one side and titanium on the other side. When we apply a voltage to the platinum, ions from solution can absorb onto the surface of the platinum, they crowd each other out, which stretches that surface and makes the actuator bend. You apply the opposite voltage, the ions leave the platinum, and now the actuator goes back to its original shape. So the ability to do this with voltages was a big deal, because now you can start to interface with electronics.

David Nutt  08:30

And so now, where does light fit into this with the diffractive robots?

Itai Cohen  08:34

We wanted to start to think about now that we could make these robots at the micron scale. The robots that we were making were maybe 100 microns in size. Just for comparison, that's about the diameter of a single hair from your head. So these robots had full blown like electronics and actuators. They could run on their own across surfaces, just when exposed to light, the electronics would take care of coordinating the leg motions, and we started to understand that now that we were functioning at this scale, we could actually interact with light itself. So the idea here was to make surfaces that were so small that the light, which has a wavelength on the order of few 100 nanometers to almost a micron, would be able to interact with the features of the robot itself. And once we understood that, then we were again off to the races trying to make microscopic robots now with features that were small enough that they could manipulate light itself. So the idea here was to make little lenses, diffraction gratings, and to use these kinds of optical elements to now interact with the microscopic world in a completely different way from the way we had been doing it before. So previously, if we wanted to look at microscopic systems, we would maybe use a microscope to look through a lens, which gave you high magnification. Now, these robots can act as little appendages that do our bidding, and we can interface them with the microscope and have sort of extra little tentacles that walk around our substrate and are measuring forces and are, you know, focusing light further, taking images and using them to reconstruct features that couldn't be resolved by our microscope. So all of this now becomes available as these little robots become thousands, if not hundreds of thousands, of little appendages that can roam around your surface and enhance the optical microscopes access to the microscopic world. 

David Nutt  10:51

So it's funny that you mentioned fear before, because every time we talk and you describe like, like, what you're building and, and, and what the future is going to look like. And you've mentioned, you know, micro bots, you know, in the body, tracking disease, scrubbing the blood. And part of that is fascinating and part of it just fills me with terror. Like, is that really something we need? Is that something you think about? How is this going to manifest, and how are you gonna, how do you prepare people for for a future where there's gonna be technology inside them, right? You know, fixing their bodies? 

Itai Cohen  11:30

Yeah, I get it. When the pandemic was going on, I remember this huge outcry about how Bill Gates was putting little, tiny, microscopic circuits in the vaccines and tracking every one of us. And I was like, why is Bill Gates getting all the credit for the things that we do in our lab and and why isn't he giving us at least some money to, like, conduct this research? But okay, I mean, the real the - so I understand the fear. I think a lot of people come to me with the same sort of questions about, you know, what are the ethical responsibilities here? And I don't want to brush those aside. I think there are significant ethical responsibilities that we have as scientists to make sure that our technology is not doing any harm in the world. It's complicated. Those are often very challenging questions. But let me, let me sort of take some of the concerns that people have, and try to debunk them a little bit, right? So, first of all, we don't use these things to track people, right? Bill Gates can already do that with your phone, right? Or, in this case, Steve Jobs, God rest his soul, right? Could do it with your phone, right? They're already tracking you. You don't need to put a micro circuit, you know, inside your body, and those micro circuits really wouldn't be powerful enough to transmit information to some satellite that's kind of looking at you right, like that's not how we do it. Another big fear that people have is the gray goo, you know, the sort of robots making other robots, making other robots and taking over the world. And let me just say that the machines that we use to make these robots are, of course, enormous, right? We are fabricating these using the same technology that is used to fabricate the electronic circuits that go into your phone, CMOS circuits that are driving all the processes that are going on in there. And, you know, these facilities are massive, right? We're not talking about something that can be done in a laboratory. You really need massive, massive machines that can project patterns onto surfaces and etchings that sort of, you know, build this up. And our robots are made using exactly the same technology, and there's no way that our robots could manufacture other robots, because they don't have access to these massive machines. That scale is out of their bounds. So our robots are not particularly adroit at manipulating molecules. They're actually pretty clumsy in some sense, and even as we learn to control them better, it's not really going to be something where they can manipulate molecules in order to make other robots like themselves. That can only happen using these very sophisticated technologies. So those are some of the questions that people have in terms of having these robots inside of us. You already have technologies like that. So these days, when we put heart pacers in, we don't really do a big pacer with like electrodes that sits outside your body. No, we we actually go in with a little catheter and we implant a pacer inside your heart. And when that pacer goes bad, we leave it inside your heart, and we put a new pacer in so you already have technologies like that that are inside your body, inside many people's bodies, that are already functioning and have proven very advantageous. People are working now on trying to implant sensors for glucose monitoring and then the idea would be to have little, tiny actuators that release insulin on demand, instead of having it pumped externally. And the usefulness of that is that you don't have like, a tube going through the skin and giving you the possibility for infection. So I think the idea of having machines inside of us that's already something that's that's happening, and our goal is to make it easier for people like doctors to do surgeries on length scales that are 10 times smaller and more delicate than what they can do now and maybe someday - and I want to be careful about this, because this is really a long ways off; it's not something that we can do tomorrow - but maybe someday, you know, these robots, in addition to acting as surgical tools, maybe they could have enough autonomy to search through a wound site and clean it of cells that are bad for the wound, maybe necrotic cells. Maybe you could have an incision that's open, and these robots with enough autonomy could hunt down cancer cells that maybe weren't detected by the surgeon and then help us do things better in these kinds of very challenging surgical situations. 

David Nutt  16:18

That's great. You know, it occurs to me when we have these conversations and you're sort of projecting out, and I sort of get a glimpse of, like, the speculative future, and it's all very sci fi and cool. When you were a kid growing up, were you like, were you like, a sci fi junkie? Were you, like, really into robots? Or is this something that just developed because of your interest in materials and and science? 

Itai Cohen  16:41

No, I was definitely a sci fi junkie, right? I grew up on Star Wars and Star Trek. What's funny to me is that my kids, when I tell them that I make these microscopic robots, they are thoroughly unimpressed. They're like, when are you going to make a robot the size of a house for them? You know, making something big is the key. I don't know. Maybe they'll grow out of it, but yeah, no, for me, like the microscopic robots world, what's interesting about it is that I've kind of grown up with that science fiction all along. Right? The Borg had, you know, nano scale robots that were somehow, you know, connecting circuits to neurons in the machine brain interface. Nanoscale robots are everywhere in the Marvel Universe. Iron Man has a little backpack full of them, and they make up his Iron Man suit, right? So this stuff is kind of all around you. In the sci fi world, it's almost like a solved problem. But in the real world, it really hasn't been doable until we started creating these, these technologies. That's where, you know, when you start to realize, oh my god, we're going to be able to do this, then all of the sci fi things go, well, you know, could we make that? And could we make that? And, you know, like, what about this? And then that sort of nice conversation between the imaginary and the real world can take place. And I mentioned earlier that during the sabbatical, you sort of have these moments of crises. I think what really came out of my sabbatical was this idea that that you sort of need to lose the sense of fear, and it's really hard to do until you know all of your I don't know, until you deal with some of your baggage, or maybe all the promotions are behind you. But there's this sort of feeling of like, hey, you know, I've got 20 more years to make this work. Like, what could we do? And let's try to do that. And if there's nothing that's physically stopping us, in other words, if there is no physics law that we're violating or some sort of back of the envelope calculation that's saying that this is not going to work, let's try to do it. And it's amazing how well the students and the post docs have responded to this and just how much progress we've been able to make. Our first electronic actuator, electrochemical actuator was published in 2020 and four years later, we've been having these conversations constantly, like every few months or so, and that's because the developments are so rapid, and really that's due to the hard work of the students and the postdocs working in the various labs that we've been collaborating with.

David Nutt  19:29

That's wonderful. There's a very rich irony in that you're doing this like amazing, cutting edge, just really cool stuff, and you just can't see it. You can't see it to the naked eye, but you also work on large scales, also. I know that you have a project with Jenny Sabin in architecture, which is kind of an interesting, interdisciplinary project in itself, but making kirigami inspired solar skins potentially for to cover buildings or. Backyard canopies. Tell me a little bit about how, how, how that came about, and sort of what your approach is for these collaborations. I mean, you mentioned, you know, working with with Paul, and I know you collaborate with a lot of different people, and it's just, sort of, it's interesting, what, what you bring to that, and how you work in these very different scales and different areas?

Itai Cohen  20:21

Yeah, that's an excellent question and one that I am trying to figure out right now. The big picture issue in academia is that we're all taught to be siloed. So you do your Ph.D., you become an expert in some field, then you go and get a faculty job, and you are told to focus on that field so that you can become the world's expert and get tenure. The problem with that is that then everyone sort of stays siloed, right? And I didn't listen to that advice when I was a junior faculty, so I started branching out, and I don't want to I don't want to brag, but I want to sort of emphasize how much courage this took, because I told you that I was sort of riddled with fear. And being riddled with fear doesn't mean that it stops you from doing things. It just means you have to be brave in order to do them. So despite the fact that I got the advice to focus on colloidal suspensions and fluid mechanics. As a junior faculty, I branched out into areas that I absolutely had no business being in. Those included studying how insects fly, and then getting into the neuroscience behind the controls that are being implemented by the neuromuscular elements in insects. Right? So we now have a part of the lab that's doing neuroscience. I had branched into cartilage mechanics. What do I know about cartilage? Nothing, but there are people at Cornell who are experts on cartilage, and what I realized is that we had techniques that we could integrate with their expertise to do something that neither of us could do on our own. And that's sort of what happened with the origami and the microscopic robots. We started working with people who were experts in these areas, and realizing that we had ideas, techniques, strategies, that we could combine in order to be able to do things. So the microscopic robots work really required us to interface with people in the electrical engineering department who could make the circuits, material scientists who could help us investigate, you know, how these mechanisms were working, people in chemical engineering, people in mechanical engineering, who were helping us design these robots. So all of this sort of had to come together. And it's this now, like as a senior faculty, I'm seen as someone who bridges these different fields. And so people are constantly trying to figure out, well, how do you do that? Well, part of that is this sort of issue that we have in academia, of the siloing. We have to figure out how to, you know, it's not for everyone, but how to, at least for a subset of the people, allow them to have that freedom to engage across fields from a very early stage. When Lynden Archer approached me about trying to help set up this Department of Design Technology out of the architecture school. I was really interested in that, because the idea was to try to create an environment where faculty could do that from the beginning. And so this is really what inspired me to work with Jenny and help try to get this department off the ground. We want to think about, how do you develop a cadre of individuals that can really take advantage of the wealth of technological expertise and resources and equipment and facilities here at Cornell to sort of span and reach across departments and create that cadre of people who can really see the opportunity that exists when you put these fields together. As an example of that, that's where all this research with Jenny on creating helioskin, which is this morphing skin that we want to wrap structures with. That's where that research came out of - this idea of trying to create this sort of interdisciplinary approach to developing technologies. And what we realized is that many of the things that we were trying to do at the microscopic scale with our meta material robots, another class of robots that we're developing, we could apply at the macro scale, and now you could find applications in completely new domains, including trying to get photovoltaics onto skins. And the big idea there is that you could print this skin in 2D but by making cuts into the material in very specific ways, you could create a kirigami - that's like origami with paper cuts art form. You could make a kirigami sheet that you could stretch locally, and even though you're printing it in 2D it would be able to morph and wrap three dimensional objects that have curvature. And that's where this idea for wrapping buildings came from. Could we make a beautiful esthetic photovoltaic surface that would allow us to wrap these buildings and allow them to solve some of their ecological challenges, which is like to reduce the energy usage and at the same time be esthetically pleasing and not sort of ugly, like the sort of current flat solar panels that everyone has on their roofs. Those cannot be tiled onto curved roof surfaces, for example, so you'd never be able to get that onto a Frank Gehry building. But maybe if we could make a morphing sheet that could adapt to the curvatures of these beautiful structures, then we could integrate photovoltaics in an esthetically pleasing way.

David Nutt  26:21

So what's next? Like, what are you really excited about?

Itai Cohen  26:25

Oh, there is so much that's going on. It's really been dizzying. We have - I'll give you a couple of things that are sort of in the distance. One of them is that we've started to think about making materials that combine electronics at the most fundamental scale of the material. So what do I mean by that? There are classes of materials called metamaterials, where you can, let's say, cut them up in some way, so that they're composed of a region that's made of, let's say, a stiff elastomer, like a plastic, and then another region that may be hollow, made of air. And if you put those two elements together, you can get something that has neither the properties of air nor the properties of some elastic material, right? So you can create by patterning the material at some medium length scale, you can create macroscopic properties that you would never be able to see in the constituents that are making up that material. So, for example, if you hold a banana in your hand and you smoosh it, usually it'll come out the top and the bottom. But if you make one of these auxetic materials, which has this combination of plastic and air, if you squeeze it in one direction, it might actually contract in the other direction. So that's an example property. So now what we want to ask is, well, what happens now if you start incorporating electronics at that medium length scale? So what if now the electronics are an integral part of the material? What could we do with that? So if, for example, I have a normal material and I whack it on one side, sound waves will propagate the deformations from that one side to the other side of the material. But if I have electronics that are communicating from one side of the material to the other, those electronics could communicate at the speed of light. That means that the material could react to the incoming sound wave before the sound wave even gets there. So that opens up the ability to completely reimagine what materials are are about, like we can program them. We can drive, you know, each of these electronic circuits could actually use light to pump energy into the micro scale interactions of the different elements that are making up the material. And so all of a sudden your material becomes something that is, you know, that was completely unimaginable with passive even metamaterials that we could make before, okay? And so we're calling these materials elastronic materials. These are really, I think, a complete leap in what we're going to be able to do in material science, right? It's a it's a complete sort of redesign of the of the borders of what's possible. Another area that we're very excited about, and this has to do with the other hat that I wear. We discussed earlier that I study insect flight, and so one of the really fun parts of the insect flight is that it's kind of led to areas that I never thought would be possible. One of those areas is really trying to understand the inner workings of how flies move about their world. We know a little bit about the aerodynamics. We've done some work in my lab to figure out how they implement controls. But nowadays, I don't know if you saw it, but in The New York Times it was published, we have the complete connectome for the fly brain. We know how the how every neuron in the fly brain interacts with every other neuron. We know all the synapses, and what that does is it allows us, it gives us a map of the of the neural connections. And in addition to that, this is work that was really spearheaded by the Howard Hughes Medical Institute, we've been developing libraries of flies where we can shine light on them and turn individual neurons in that map on and off. So we can essentially, sort of pick a neuron, turn it on, and see, then in our free flight apparatus, how that changes the behavior of the fly. Okay, so why am I going on and on about this? Well, we've just made an actuator that allows us to work in air. So in the previous actuators, the electrochemical actuators, they were all submerged in a fluid because we needed to absorb ions from solution. But we now have an actuator that carries the ions with it, and it can function in air, and we can operate it at about 100 hertz to 300 hertz, and we've just put a wing on top of that actuator. So what does that mean? So we're going to be able to actuate a 300 micron wing at 300 hertz, and that puts us in a position to make a microscopic flying robot that is about a millimeter big. And the really fun part about that robot is that we're going to have to completely reimagine robotics, because when a big, macroscopic robot walks into a new environment, it uses lasers, and, you know, LiDAR, to kind of detect its surroundings and map the room. And then it uses a really complicated processor to figure out, you know, how to plan trajectories from one spot in the room to another, avoiding obstacles. Blah, blah, blah, blah, blah, blah, right? That is way too much computational power. We're never going to be able to put that on a millimeter scale robot, but if we start understanding how insects do it with 100,000 neurons, we're going to start to learn the way that we can start to manufacture robots which use much less power, that are much more simple, that are sort of able to understand their location in their world using much simpler algorithms. And right now, in the field of fly neuroscience, we are discovering those algorithms. It is unbelievable. We know how flies can add vectors in order to determine which direction they're heading. We know how they can add vectors to figure out that even though they're heading in, you know, let's say the North direction they're moving, east or west, right? So flies have this very amazingly beautiful circuitry. They literally have like compass neurons, neurons arranged in a circle that tell them which direction they're heading. And so all of this kind of beautiful circuitry we're going to we're learning, and the idea is to make simple robot analogs that are using these kinds of approaches in order to reimagine what robotics can be at the micro scale. And that's again, something that you could never get if you were siloed in some field, right? It really requires this excursions into these other areas, these other realms of neuroscience, insect flight and robotics in order to put something together like that,

David Nutt  34:03

I was just starting to feel okay with the idea of micro robots in my my blood, and now, now I have to worry about about flying, flying micro robots too?

Itai Cohen  34:14

Yes, okay, right, good, yeah.

David Nutt  34:16

Well, it's so in conclusion, let me ask, where is your fear at these days?

Itai Cohen  34:23

Well, from a personal perspective, I feel I've somehow managed to be brave enough to overcome my own demons. But when I look at the world at large, the fear comes back. Look, science always produces technologies that can be used in one way or the other. The real fear is not in the technology, it's in how we use it. And so my biggest fear is not in the technologies that are being developed. You know, we currently have technologies to destroy the world, you know, 18 times over. The real fear is that we've become so divided as a world that all of a sudden people are starting to use these technologies against one another, and I feel like that's the part where we need to do work. I know that everyone is really into STEM, and there is a lot of fun, exciting things that are happening in STEM but if we don't get our social structure under control, we are going to be doomed as a civilization. And it doesn't really matter what new technologies we make, we already have the ones that are going to be able to destroy us multiple times over. So we got to get our social structure under control. We have to figure out how to talk to one another. We have to figure out how to deal with misinformation and social media, this new platform that has completely changed the discourse in our nation and those of others. And we have to have political solutions, rather than violent solutions if we want to save our species. We've got to deal with climate change. You know, it's not about one degree or two degrees here or there, right? We just don't really know how much change is going to drive us to a tipping point where the climate becomes so erratic that we cannot grow enough food in a reproducible fashion to feed the planet. So I think those challenges are many of them are political, and I really hope that people go into these social sciences fields and figure out how to solve these problems, because without that, it doesn't really matter what happens in science. We're, we're going to be in deep trouble.

David Nutt  36:43

Well, if there's one thing that I think most people can agree on, it's that robots are pretty are pretty cool. So, so yeah, you're doing you're doing your part.

Itai Cohen  36:52

We're doing our part. And I think robots are going to be important, especially as we start to have a workforce that is older. If we don't have a sort of significant rise in population, then again, you're going to need robots to do a lot of these very important manufacturing tasks, and God forbid, if we really keep going with the decimation of our insect population, which is a big crisis, also another one that has the potential to massively affect our planet. I mean, just to, just to sort of put it out there, right, like before insects took flight, you know, there were no flowers, right? There were no trees, like all plants were less than three meters tall. So if we keep decimating our insect populations, there's not going to be any fruit. There's not going to be any - the whole sort of variety of life diminishes. Without pollination, we're going to be in deep trouble. So God forbid that that ever happens. We might even need robots to pollinate, which is kind of crazy to think about, but, I mean, we're pretty you know, what's scary is how close we are to that situation. Robots are cool. I think they they have some sort of way of capturing the imagination and showing us what's possible. But what's amazing to me is that, you know, I work around robots all the time, but when I look at my children, the kinds of things that they can do, they're six and four, you know, massively outstrip what robots can do. You know, people are the amazing, the amazing thing on this planet, and we've got to do everything we can to preserve, you know, our society and the amazing things that we've been able to do thus far. And I hope we're,  hope we can play a small part in helping to make that happen.

David Nutt  38:58

Itai, want to thank you for taking the time to talk with us. It's always a pleasure.