Podcast: Meet the World's Smallest Walking Robots

In this episode, we dive into Cornell University's groundbreaking development of the world's smallest walking robots, measuring between 2 to 5 microns. These micro-robots will likely revolutionize microscale measurements, offering unprecedented precision in scientific research and engineering applications.

This podcast is sponsored by Mouser Electronics. 

Episode Notes

(2:30) - Smallest walking robot makes microscale measurements

This episode was brought to you by Mouser, our favorite place to get electronics parts for any project, whether it be a hobby at home or a prototype for work. Click HERE to learn more about another micro-topic - micro-mobility - and how it will/already is changing our urban infrastructure!

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Transcript

Welcome back to The NextByte, folks.  And in this episode, we are talking about why one of the smallest new things in the medical and robotics realm might just be one of the biggest breakthroughs that we've talked about so far. So, if that little teaser piqued your interest, then buckle up and let's shrink down.  

What's up friends, this is The Next Byte Podcast where one gentleman and one scholar explore the secret sauce behind cool tech and make it easy to understand.

Farbod: Welcome back to another episode of why size matters here at The NextByte. But before we get into that, let's talk about today's sponsor, Mouser Electronics. Now folks, if you've been rocking with us for a minute, you know we love working with Mouser. That's because they're very similar to us in the sense of wanting to share the cool things in the tech and STEM world with the average listener. And they do this by creating these incredible technical resources. One of them we have linked in the show notes today that talks about a variety of things.   For example, the one today is talking about micro mobility solutions and how they will shape the future. You might be wondering, well, what does that even mean? Well, dear friend, Mouser is here for you. They're talking about last mile delivery. Big cities, you might have, I don't know, like us, Daniel, like we live close to Washington, D.C. It doesn't really make sense to bring out big trucks to deliver packages or have massive vans, moving around the city for dropping off little packages or food deliveries and things like that. They talk about all these innovations that are happening which are creating micro mobility devices. It could be compact cars. It could be compact autonomous systems. One of those was kicked off in the university that Daniel and I went to, our alma mater, Georgetown University, where these Starship Robotics robots, these tiny little white robots that are called nicknamed marshmallows, will bring you your food to your class instead of requiring a human being to do it or, I don't know, another service. So, they're going on and on about all these different breakthroughs in technology that are enabling these last mile micro-mobility solutions and why they're better for the environment and more convenient for the user, things like that. And it's kind of the perfect segue to what we're talking about today, which is the world's smallest walking robots, again.

Daniel: Mouser, we take your micro-mobility and we raised you micro-robots.

Farbod: It's a big, world out there, but when it comes to robots, things are getting small, in a good way, right? And today, we will be going over to Cornell University, and we haven't been there in a minute, but it's crazy that they're the ones that, not crazy, it makes sense that they're the ones who made the world's smallest walking robot because they held the record for the world's smallest walking robot before this.

Daniel: Yeah, so if you're going to bet on someone to make the world's smallest walking robot, it's probably the people who have already made the world's smallest walking robot. They're just going to beat their own record. And that's exactly what they did here.

Farbod: Exactly. they, so before this new thing that we're talking about, the robot they had, which was breaking records was 40 to 70 microns. Now for some context, the average human hair thickness is 70 to 80 microns.

Daniel: Okay, so they made a tiny robot that is as wide as the width of a hair.

Farbod: A tiny walking robot, as thick as a hair, a strand of hair, or even smaller.

Daniel: And that was the old record.

Farbod: That was the old record. And they decided this isn't good enough. We have to go smaller. But Farbod, why smaller? Great question, audience. They're talking about how, you know, right now, if we try to do imaging, especially in the medical realm, right? Like you're using microscopes, that's the go-to. You have this big, massive piece of equipment that allows you to do imaging, zoom in on cells or whatever, which is great. But they had this idea of, wouldn't it be great if we could embed a microscope in the region that we're trying to analyze, which makes a lot of sense, get on the ground floor, see what's going on. But on top of that, what if we could have structures that are sensing what some of the smallest structures of our body are experiencing and get measurements that way as well? That's great. Like you're doing imaging and you're doing some sensing of all that other stuff. And the question was, can we do sensing and imaging at the tissue level? Like in the tissue.

Daniel: Not just like next to the tissue, in the tissue.

Farbod: In the tissue. And this is a perfect, like intersection of optical engineering and material science, some of the things that Cornell is very good at. And the idea they settled on was light diffraction. So simply put light diffraction is the bending of light. And it happens by light moving through an object or moving around an object with the caveat being that if it's moving through the object, it needs to have an opening that is the same size as the wavelength of the light that is moving through. So visible light, like the thing that we're observing on a day-to-day basis, that has a wavelength of four to 700 nanometers. So that if you want to have an object that is able of diffracting visible light, needs to have an opening of four to 700 nanometers. That's the general idea. And that's no small feat. 400 to 700 nanometers is very small. Again, go back to what we were saying earlier, 70 nanometers is the thickness of hair. Now we're going down quite a bit in terms of scale. And long story short, they achieved it. They created a robot like that. But what does that even mean? Like how does a robot work? How does it move? How does it help you image? How does it do any of those things? Well, I'm gonna walk you through this.

Daniel: Because it's a walking robot. So why?

Farbod: Thank you. Thank you for catching that. Let's start off with motion first, they're able to have an array of these little nanobots, nanoparticles, let's just say. And they pattern them with magnets.  They pretty much deposit magnets all over them. And there's two types of magnets that are being deposited on these particles. There's these short and stubby ones, and there's long and thin ones. These short and stubby ones react really well to small magnetic fields, whereas the long and thin ones react really well to the big fields. Now the reason that they tune them this way is because the long and thin ones help you align all the robots together, whereas the short and stubby ones help you like move them around and flip them. And you can activate magnets outside of where these robots are to also help them move in a certain direction in this inchworm pattern because they like pinch together and then they move apart. Pinch together and move apart.

Daniel: That's really the important part here for me, for my understanding of robot. Like I was like, oh cool. They're going have something with like a battery pack and a bunch of wires and motors and it's going to drive it. That's not what they have going here. They don't have batteries. They don't have wires that are small enough to make a robot that's only two to five microns wide. In this case, there's no electrical power at all, right? This is completely powered and completely controlled magnetically. And that's the stimulus with which you can force this robot to walk. They also mentioned it can swim too. So, it's a walking and a swimming robot.

Farbod: Two for one, you know, McDonald's could never. This is the kind of that everyone hopes for. But yeah, so magnets is the name of the game here and that's how they're able to do so much of this magic of aligning them, getting to a certain location, doing all this walking and that's where the walking magic is happening. Now what's interesting is that the mechanical manipulation of these robots also kind of acts like a lens. So, like we were talking about earlier, light diffraction, it's how light is bending by going through these robots in this case. Well, they also realize that they can change how they're sorted or they're arranged and it gives them different types of magnification into what they're looking at, which is quite impressive. And then in terms of imaging, I had mentioned that it would be great if these researchers had a way of understanding how microstructures in our body respond to what's around them. One of the researchers said that these robots are perfect springs. As you have forces pushing on the robots, they start bending just as they would if they were walking, but as they bend, the diffraction also changes. They bend light differently. So, they can measure the amount of force being applied to different robots by just looking how the light is bending, which is another big unintended win, or maybe intended in this case, honestly.

Daniel: Yeah, no, it's awesome, right? So, they’ve got several sets of magnets, short ones flip with weaker magnetic fields, long magnets flip with strong magnetic fields that creates this inchworm like structure that can inch around to walk or to swim. It's got built in optical parts, these diffractive lenses that bend light. Think about the applications here. So, in addition to measuring how much light bends to measure forces on these tiny robots, you can also use the tiny robots, their lenses, so to speak, to focus or to zoom light if you're trying to take an image.  One of the things that the researchers mentioned is like you could treat a bunch of these robots like little tiny microscopes walking around inside tissue and they can focus to help with super resolution photos. And then also they can complete other sensing tasks related to force if you're able to pass light through these lenses and then measure the way that the light bends and changes in response to forces. In addition to having this measurement or the sensing, let's say for force, you've also got the potential application in the future to interact with the light for imaging.

Farbod: Dude, absolutely. And they're talking about how, what the future of this looks like. Like one of the quotes I liked is the researchers saying, I think we are really just scratching the surface of what is possible with this new paradigm of like bringing robotics together with this optical sensing at the nano or micro scale. So, what they're saying here in this paper is already exciting to me. This already feels like a massive breakthrough. And for them, they're like, no, no, no, this is just the beginning. Like we're barely able to demonstrate the power that this approach is going to have on imaging, on better understanding our medical discoveries, on drug discoveries, things like. Yeah, I don't know. This was a really good one. And see, I think that's all I had on it.

Daniel: I want to give a little bit of a caveat here.

Farbod: Give a caveat.

Daniel: So, when we first read this article about micro robots, can swim around inside flesh, they can take microscale measurements, I definitely thought it was more along the lines of maybe let's say a super mature robot that has sensors built in. It kind of had to redefine my definition of robot, so to speak, because it's been pigeonholed so recently into like, figure1 humanoid robots, like this the only way to build is with the human form factor. Like this is, let's say maybe the correct technical definition of robot, but a broader definition of robot than maybe we see colloquially like out in the real world. So, I would encourage everyone to keep their mind open regarding this. It is a robot, right? They've made this device that they're able to control remotely, actuate inside the human body. It's got in a, maybe not built into it, the communication method, but it's got lenses built into it that can perform different types of sensing. So, definitely something to be excited about. And I don't think that necessarily it's there yet to where we can have these, drop these robots inside my body and study things like cells or DNA really up close, but it's an important starting point is being able to demonstrate that you can make robots that are this small. They just made robots that are what? 40 times smaller than the last record, which is an incredible improvement.  And so, they're just proving now that they can build robots, the small that they can complete fine control of at like the micro or nano scale.  And I'm excited to see what comes from this right in the future when they start to test and trial medical applications that come about as a result of this development of making these tiny robots that can measure and move around at the microscale.

Farbod: Yeah, that's a good point. And to our audience, if you just don't limit your worldview of robots to the cool flashy spots that are dancing to Bruno Mars or the figure1 that's able to juggle an apple, there's a lot of fun stuff happening at the small level. This kind of reminds me of Dr. Moran's nanobots that clean water using spent coffee grounds over at George Mason. There's so many cool little things happening and I don't know, it just slips past the news because they can't shuffle right.

Daniel: It's because they're too small. They're too small to get picked up by traditional media, but not by the NextByte.

Farbod: Not by the NextByte.

Daniel: That's why we exist, folks.

Farbod: We're here for the little guy.

Daniel: Yeah, size matters.

Farbod: Size matters. All right, so folks, to wrap it up, researchers at Cornell made the world's smallest robot, again, making their previous record even 40 times smaller. And this robot is controlled by magnets. It bends light. And the reason it does all of these things is to better image tissues.  Instead of having microscopes outside and then looking in, what if you just had them embedded at the tissue level? Some of these scales of these robots can mimic the smallest structure of our body so it can sense what's going on in there as well. The force is pushing against it, whatever else is going on. And what's crazy is that although this is already unlocking a lot of value, giving us the insight that we need and helping with drug discoveries and whatever, this is just the beginning. This is the start of what this technology can bring us. And that's why, even though it's so small, it might just be the next big thing in the medical realm. That's it. That's the summary. You like that? All right.

Daniel: Yeah. That's awesome.

Farbod: That's the pod.

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The Next Byte: We're two engineers on a mission to simplify complex science & technology, making it easy to understand. In each episode of our show, we dive into world-changing tech (such as AI, robotics, 3D printing, IoT, & much more), all while keeping it entertaining & engaging along the way.