The RoboBee sits on a fingertip.
Courtesy of Harvard Microrobotics Laboratory
We’re talking all about teeny, tiny robots in today’s episode. You know, the ones that are as light as a postage stamp and as look like insects? They may be small, but these robots can still take in information and make decisions on their own. Find out how bees and cockroaches are teaching us about the future of small robots and what big tasks they might take on. There’s also a new Mystery Sound to rattle your ears. Plus a moment of Um that answers the question: Why does the sun stay in one place?
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- You're listening to "Brains On!" where we're serious about being curious.
- "Brains On!" is supported in part by a grant from the National Science Foundation.
MARC SANCHEZ: Molly, Eva, I know you're about to go tape the episode, but I have to tell you about this dream I just had.
EVA: Sure. Listening to people recount their dreams is never boring.
MOLLY BLOOM: Oh, yeah. Remember when I told you about that one where I was waiting in line for a smoothie but then a dog came up to me and handed me a cup of tomato soup instead? And then the dog took me on a walk, and we made like 20 different stops at shops and parks and stuff and I told you about every single one?
EVA: I remember vividly.
MARC SANCHEZ: Well, wait until you hear about this. In my dream, I had invented this tiny little robot. Basically, it lived in my shoes and whenever I put them on, it would crawl out of a small hole and tie them, no hands necessary. And then it would just crawl back when it was done. And when I wasn't wearing the shoes, it would destroy all the odor-causing bacteria inside. What an amazing robot! It was called--
[SIGHS]
[CHIMES]
--the shoe crab.
EVA: Horseshoe crab?
MARC SANCHEZ: No.
[SIGHS]
[CHIMES]
The shoe crab.
MOLLY BLOOM: That sounds so useful and adorable.
MARC SANCHEZ: Friends, this dream was a wake-up call. I need to build the shoe crab. I mean, I already invented it in my brain. Now I just need to figure out how to make it real. To the tinker table! Don't worry, shoe crab. I shall free you from my mind.
EVA: Good luck, Marc.
MOLLY BLOOM: Wow, that's amazing. We should head to the studio. But first, I need to tell you about this other dream I had. For some reason, I was dressed like a baby from an old cartoon, like, in a onesie and a bonnet and with a pacifier in my mouth. And all around me were tiny Caesar salads. And I just hated the smell.
[THEME MUSIC]
You're listening to "Brains On" from American Public Media. I'm Molly Bloom, and my co-host today is Eva from Fond Du Lac, Wisconsin. Welcome.
EVA: Thanks for having me.
MOLLY BLOOM: So, Eva, what is your favorite robot, real or fictional?
EVA: My favorite robot is probably a real robot named Spot, and he was made-- or it was made-- in Boston Dynamics. And I find it really cool because it can do things such as, like, deliver things. It has its own camera to see things that humans can't. It can help with research. It can open and hold doors for people. And it's, all in general, just fun to watch.
MOLLY BLOOM: That sounds like a very, very cool robot. I've never seen it before. So can you describe what it looks like?
EVA: It's, like, kind of shaped like a dog. It's very yellow. And it walks like a dog too.
MOLLY BLOOM: Wow. What do you think of when you think about robots in general?
EVA: When I think of robots in general, I think of them as, like, mostly helpful. But some people, they do think of them as, like, evil and trying to take over our world and not letting humans do what they usually do. But mostly when I think of robots, I think of them as helpful and they could change our world in the future.
MOLLY BLOOM: Yeah, robots are a lot of fun to think about. And there are so many lovable robots in pop culture, like BB-8 from "Star Wars" or Baymax from "Big Hero Six" or Wall-E.
WALL-E: E-va.
MOLLY BLOOM: He's saying hi to you, Eva.
EVA: Hi, Wall-E.
MOLLY BLOOM: Now, these robots are all the size of animals or humans. But what about robots that are much, much smaller?
EVA: Right. Today's episode was inspired by this question.
GRETA: My name is Greta from Knife River, Minnesota, and my question is what is the smallest robot in existence?
MOLLY BLOOM: Before we get into it, Eva, I just want to ask you how-- when we're talking about tiny robots, how big do you imagine them to be?
EVA: Um, the smallest robot I've worked with is probably about 2 inches. So when I think of tiny robots, my imagination would probably be like so small that I can't see it.
MOLLY BLOOM: Wait, so when you say you've worked with robots, tell me more about that. You've worked with robots?
EVA: Yes, I'm in coding club, so I do a lot of coding and a lot with robots.
MOLLY BLOOM: So when you code robots, what have you been able to make them do?
EVA: So what we've been doing, they're called Ozobots. And we took these special colored markers and we would draw them in some sort of maze or pattern on a piece of paper. And then we put the Ozobots down, which are about 5 inches. And the Ozobot, according to the colors, would move a certain way. And you could coordinate them with a specific color, and you could make it spin, you could make it go really fast, stuff like that.
MOLLY BLOOM: That is so cool. So you know your robots.
EVA: Pretty well.
MOLLY BLOOM: That's awesome. So before we get into the question that Greta asked, which is what is the smallest robot, we need to begin by defining what exactly a robot is. Now, not everyone agrees on the definition 100%, but here's what a lot of people think and the definition that we're working with today.
[MUSIC PLAYING]
EVA: A robot can sense what's going on around them.
MOLLY BLOOM: Decide what to do next.
EVA: And then actually do it.
MOLLY BLOOM: So this means a remote-controlled car is not a robot because you are controlling it with a remote.
EVA: It's not driving itself around.
MOLLY BLOOM: But a real robot car would be programmed to make decisions and drive by itself. It would have what we call artificial intelligence.
EVA: When a machine can make decisions and move on its own, we call that autonomous, or we say it has autonomy.
MOLLY BLOOM: Real robots are autonomous.
EVA: So what's the smallest robot right now?
MOLLY BLOOM: This is tricky to answer. There are a lot of machines out there that are tiny that are being called the world's smallest robot.
EVA: But they can't do much on their own.
MOLLY BLOOM: They can be controlled by magnetic fields or infrared light or even vibrations. And some of them are super-duper tiny. You would need a microscope to see them.
EVA: Which is super cool, but it's closer to a remote-controlled car than one that drives itself.
MOLLY BLOOM: Researchers are working on making them fully autonomous robots but they're not there yet.
EVA: One of the contenders for the title of smallest robot that can do all the things we talked about is the Kilobot.
MOLLY BLOOM: It's about 3 centimeters, or as big as a quarter.
EVA: So why aren't tiny robots even tinier? And why aren't there more of them?
ILLAH NOURBAKHSH: Yes, small robots are hard.
MOLLY BLOOM: That's Illah Nourbakhsh. He's a professor at Carnegie Mellon University in the Robotics Institute. He's also written the books "Robot Futures" and "AI and Humanity."
EVA: He spends a lot of time thinking about robots and the way humans relate to them.
MOLLY BLOOM: And he says there are many reasons why building tiny robots is tricky.
ILLAH NOURBAKHSH: One of them is physics changes when you start making things really small. Things become sticky.
MOLLY BLOOM: You know how a gecko or a spider sticks to a wall? They have tiny hairs on the bottoms of their feet that are attracted to the wall through something called Van der Walls forces.
EVA: Those forces can make tiny robots stick to stuff too.
ILLAH NOURBAKHSH: Suddenly, you're stuck to surfaces that you weren't intending to stick to because you're accidentally kind of suctioning to them.
EVA: And sometimes, instead of being sticky, tiny robots will be slippery.
ILLAH NOURBAKHSH: So if you're trying to get friction down to the ground so your wheels will turn properly, they might just slip because the thing is so light it doesn't really have viscous friction with the ground very well.
MOLLY BLOOM: Another problem is powering the robot with electricity.
ILLAH NOURBAKHSH: And as you make a robot really tiny, you have to make a really tiny battery. And that's both physically difficult because the battery is an actual chemical system, so it's hard to make it small. But it still has a microprocessor, it's still thinking-- whatever the computer version of thinking is-- and that takes a lot of power. And that's going to drain your battery pretty fast.
MOLLY BLOOM: So tiny robots are hard because they can accidentally stick to things or sometimes they slip and slide too much, and it's hard to make batteries teeny enough to power them.
EVA: Plus a lot of equipment and materials you would need to make tiny robots don't necessarily exist yet.
MOLLY BLOOM: But there are indeed some pretty small robots that have some level of autonomy.
EVA: And they have something in common.
MOLLY BLOOM: They were inspired by insects. We asked "Brains On!" producer Menaka Wilhelm to look into that. And, oh, hm-- Menaka, you did more than just look.
MENAKA WILHELM: Of course I did, Molly. I really wanted to understand moving like a bug. So I made these cockroach-inspired shoe covers.
MOLLY BLOOM: Oh, wow.
MENAKA WILHELM: Now I can scuttle. Oh! Please hold still. That sound is too -ish for me. OK, I get it cockroaches are not everybody's thing. But they've managed to solve a lot of the problems you mentioned. They're small. They can move around without too much sticking or slipping, and they do it all without running out of power. So why not try to model tiny robots after cockroaches or other bugs?
MOLLY BLOOM: It makes perfect sense. If nature already figured out a good design for a tiny autonomous thing, why not try to learn from that?
MENAKA WILHELM: Precisely. A lot of scientists are doing just that. And it turns out scuttling like a cockroach is actually a great way for a robot to get around. Kaushik Jayaram is an engineer who has worked on cockroach-inspired mini bots.
KAUSHIK JAYARAM: Cockroaches are excellent at running really fast. They can climb up walls just as easily as they can run on level grounds or along ceilings. They can easily squish into really small gaps. And they are seemingly indestructible.
MENAKA WILHELM: The robot that Kaushik and his team made looks a little like a tiny matchbox with four legs. It can run in different directions, just like an insect. And it's not quite as fast as a real cockroach, but it does have one robo talent that cockroaches don't-- it can run backwards.
EVA: Cool. Also a little icky.
MENAKA WILHELM: Well, here's another insect inspiration that might have a lower ick factor-- the flea. Fleas are master hoppers.
SARAH BERGBREITER: Jumping is kind of nice when you're small because you can handle all of the kind of rough terrain and obstacles that might be in your way.
- Sarah Bergbreiter has worked on a bunch of little bots that spring into the air to move around. One looks a little like a tiny upside-down palm tree. It's about an inch and a half tall with four feet at its base, and its little parts are programmed to press down a tiny spring--
[BOING]
--and then release it to jump into the air.
SARAH BERGBREITER: And this is the way jumping insects work too. So they store energy in a spring and they release that suddenly to get the very high acceleration and high power that they need to jump.
MENAKA WILHELM: Fleas don't use metal springs. They just have springy parts of their legs that work like this. And that's what the flea bot is copying. Eventually, the idea is that the flea bot could jump around or hitch a ride on other beings the way fleas hitch rides on cats and dogs. And besides being small and moving well, bugs are also great at working in groups, which brings us to another insect that's inspired engineers.
FARRELL HELBLING: So you think about bees. They're normally in hives. So how do they work together and how do they work as individuals?
MENAKA WILHELM: Farrell Helbling is a researcher at Harvard. She's working on a little robot called the RoboBee. It's got two wings and four little legs, and it's tiny. These robots weigh 80 milligrams, which is about as much as a postage stamp.
FARRELL HELBLING: They're very, very light. Whenever I hand one to people, they're like, oh, my gosh.
MENAKA WILHELM: And because they're so small, it would be very hard for a RoboBee to do much on its own. But in a big group, or a swarm, small things can be very mighty. Here's Sarah again.
SARAH BERGBREITER: So if you think about the ants in your yard, they can carry off your bag of potato chips if they want to, even though each one is very, very tiny. But if you have enough of them, they can really wreak havoc on your lunch.
EVA: If only we could program RoboBees to stop those ants from stealing our lunches-- now that would be useful.
MENAKA WILHELM: Yeah, leave our lunches out of this. Tiny things can also use that teamwork to build big stuff. Some termite colonies have built nests that are 30 feet high. So other researchers have taken a page from that termite handbook and made little builder bots.
And here's what's really cool about these termite-like robots-- they don't have to talk to each other to work as a team. All the termite bots just have the same goal-- stack blocks to build a structure. And then each individual robot just figures out what it needs to do on its own to make it happen. Pretty amazing.
EVA: Teamwork makes the dream work for people and tiny robots.
MENAKA WILHELM: But at this point, real insects have robo insects beat. They've adapted to survive and move in incredible ways. So before I go, I have to mention that some scientists are trying to add devices to real, live cockroaches so they can move those bugs with remote control. It doesn't work perfectly. One team did it by strapping little bug backpacks onto cockroaches.
MARC SANCHEZ (AS COCKROACH): Oh, cool backpack. Am I headed to school?
MENAKA WILHELM: My cockroach friend, nope. Your backpack is actually a tiny little computer. It's going to tell your legs where to go.
MARC SANCHEZ (AS COCKROACH): What a wild idea.
MENAKA WILHELM: Well, that's time for me to scuttle. Catch you all later.
EVA: Bye, Menaka.
CHORUS: Ba ba ba ba ba ba ba ba ba ba Brains On!
MOLLY BLOOM: Now, before we move on, we have something for you to sense and then react to. It's the--
- Shh.
[OSCILLATING]
Mystery Sound.
[OSCILLATING]
Here it is.
[BOUNCING, VIBRATING]
OK, Eva, what is your guess?
EVA: Maybe it's like a robot that could be like vibrating, like, something vibrating, I feel like, that gets more vibration every single second.
MOLLY BLOOM: Yes, I heard some vibrating noises too. We're going to listen to it again and have another chance to guess in just a bit.
[MUSIC PLAYING]
EVA: If you have a question you want to hear answered on "Brains On!", maybe a mystery sound or drawing to share--
MOLLY BLOOM: Maybe a drawing of Marc's shoe crab, send them to us. Just go to brainson.org/contact.
EVA: That's where we got this question.
ADIA: Namaste. My name is Adia and I'm from La Crosse in Minnesota. My question is why does the sun stay in one place? Can't it move around like Earth?
MOLLY BLOOM: We'll be back with an answer to that during our Moment of Um at the end of the show. Plus, we will read the most recent group of names to be added to the Brain's honor roll.
EVA: So stick around.
[MUSIC PLAYING]
You're listening to "Brains On" from American Public Media. I'm Eva.
MOLLY BLOOM: And I'm Molly. It's time to get back to that mystery sound. And before we listen to it again, I'm just going to tell you that it does not have much to do with robots at all.
EVA: OK.
[BOUNCING, VIBRATING]
It kind of sounds like a bunch of, maybe, like golf balls, like, dumping a bunch of some sort of balls into, like, a cup or something and it's making that vibrating noise.
MOLLY BLOOM: That is a really incredible guess. Here is the answer.
ROWAN: Hi, my name is Rowan, and I'm 6 years old from Toronto. And that was the sound of me dropping a golf ball into a rain gutter pipe.
MOLLY BLOOM: Eva, I am so impressed. That is so incredible. When we chose that, we're like, oh, this sounds so cool, but it seems really hard to guess. But no, you had no trouble. A golf ball in a cup is so close to a golf ball in a rain gutter.
EVA: Um, I lived next to a golf course and I do golf, so--
MOLLY BLOOM: So you have some familiarity with the sound golf balls make in different circumstances.
EVA: Yeah.
MOLLY BLOOM: I love that. Excellent, excellent guess.
[AUDIO LOGO]
There are lots of smart people working on making tiny robots that could help humans and our environment in lots of different ways.
EVA: There are so many possibilities. That's why it's so fun to imagine what the future looks like.
MOLLY BLOOM: And a lot of you have ideas for what you want to see.
PENNY: My name is Penny, and I'm from Bozeman, Montana. And my little robot would be a flying, sword-fighting robot that would fly around you and sword fight the mosquitoes that tried to bite you. And it would sound like this-- [IMITATES SWOOSHING].
ANCHU: Hi, "Brains On!" This is Anchu from Toronto, Ontario, Canada. My tiny robot would be able to brush my teeth for me, and it could do it in two seconds.
VAN: Hi "Brains On!" My name is Van and my robot would clean up all my toys and give me money. And it's sound would be [IMITATES WHOOSHING].
SYDNEY: Hi, my name is Sydney from Boulder, Colorado. And my little robot would clean up my room for me, give me my favorite foods, garden for me, and spray bug spray at any mosquitoes that tried to bite me.
MILAH: My name is Milah, and I'm from Castle Rock, Colorado. My tiny robot would be named Dentobot, and it would clean my teeth so I'd never have to go to the dentist. And the noise it would make would be [IMITATES WHOOSHING].
MOLLY BLOOM: Very creative thinking.
EVA: And some of those are not that far off from what scientists are working on now.
MOLLY BLOOM: There are already tiny robotic sensors that are helping filter the air to make it cleaner and healthier for us to breathe.
EVA: And robot expert Illah Nourbakhsh sees other exciting uses for small robots on the horizon.
MOLLY BLOOM: They could help clean up oil spills or help the environment in other ways.
ILLAH NOURBAKHSH: We use an incredible amount of pesticides in agriculture right now, because we're trying to, in a very broad way, get rid of the wrong species so we can grow the right species to make food. If we can create low-cost robots that can do things like literally weeding so they can physically pull out the problem pests and leave the plants, that changes the game because then we can have much less impact on the climate, much less watershed issues, and still do things like farming.
We have to get help from robotics. So I'm optimistic in the sense that we need solutions to our world's problems, especially climate change. And the only path to those solutions is going to be through really smart, community co-designed technologies. And robotics are going to play an important role in that.
EVA: Other scientists are working on tiny robots that you can wear and even tiny robots that can go inside your body. But those are still in the very early research stages.
MOLLY BLOOM: I wonder what role robots will play in our lives in 20 years or 30 years. It's fun to imagine.
[MUSIC PLAYING]
Another beautiful day at "Brains On!" headquarters. And look, our old friend Eva is here.
EVA: Hello. And this is my daughter, Eva Jr.
EVA JR: Hi.
MARC SANCHEZ: Eva, Eva Jr, I'm so glad you're here. You're just in time. It's been years of hard work, but I'm finally ready to unveil--
[CHIMES]
--the shoe crab.
MOLLY BLOOM: Oh, wow. You finally did it. Amazing.
EVA: What's a shoe crab?
MARC SANCHEZ: It can tie your shoes for you and destroy odor-causing bacteria. Oh, shoe crab.
[MUSIC PLAYING]
MOLLY BLOOM: A true robot can take in information about the world around it, decide what to do with that information, and then do it. That's called autonomy.
EVA: A lot of scientists are working on making small robots, many inspired by insects.
MOLLY BLOOM: There are some challenges in making small robots and how they behave and the parts available to make them.
EVA: But robotic technology could play a big role in solving problems, especially in keeping our environment healthy.
MOLLY BLOOM: That's it for this episode of "Brains On!"
EVA: "Brains On!" is produced by Molly Bloom, Marc Sanchez, Sanden Totten, and Menaka Wilhelm.
MOLLY BLOOM: We had production help from Kristina Lopez and engineering help from Veronica Rodriguez. Special thanks to Tim Lin, the Harvard Microrobotics lab, and Andy Doucettte.
EVA: "Brains On!" is a nonprofit public radio podcast. Your support helps us keep making new episodes.
MOLLY BLOOM: Head to brainson.org/fans to support the show.
EVA: Now, before we go, it's time for our Moment of Um.
[CHORUS OF UMS]
LISTENER: Why does the sun stay in one place? Can't it move around like Earth?
[? BRITTANY KOMAI: ?] That's a really good question. The thing is, it's hard for us to sense how much the sun is actually moving. I'm Brittany [? Komai. ?] I'm a scientist who studies the universe, and I work on building detectors to be able to see out in the universe.
In our solar system, our sun is in the center of it and we're all going around it, the same way in a racetrack then all the cars go around the same center. It's similar with the sun, is that the sun is going slowly around the center of our galaxy. But it's so slow that we don't notice it on Earth.
[MUSIC PLAYING]
So we're on Earth, and Earth is going around the sun. And we looked out, and we realized these tiny little dots were moving around. And those tiny little dots were other planets. And then we were able to put together the picture that all these planets were connected in our solar system.
When we continue to look up and look out, then we can make really, really, really precise measurements of other stars-- and so other stars similar to our sun-- and then you start to see that they're all orbiting around something in the middle. And when you start to work out the path the stars are taking, you find out there's a supermassive black hole. Like, there's a huge, huge, huge black hole. So the sun actually does move, and it moves around a supermassive black hole in the center of the galaxy.
[CHORUS OF UMS]
MOLLY BLOOM: My heart revolves around these listeners. It's the Brain's Honor Roll. These are the talented and brilliant listeners who send us their questions, ideas, mystery sounds, drawings, and high fives.
[LISTING HONOR ROLL]
Thanks.
[MUSIC PLAYING]
We'll be back soon with more answers to your questions.
EVA: Thanks for listening.
- "Brains On!" is supported in part by a grant from the National Science Foundation.
MARC SANCHEZ: Molly, Eva, I know you're about to go tape the episode, but I have to tell you about this dream I just had.
EVA: Sure. Listening to people recount their dreams is never boring.
MOLLY BLOOM: Oh, yeah. Remember when I told you about that one where I was waiting in line for a smoothie but then a dog came up to me and handed me a cup of tomato soup instead? And then the dog took me on a walk, and we made like 20 different stops at shops and parks and stuff and I told you about every single one?
EVA: I remember vividly.
MARC SANCHEZ: Well, wait until you hear about this. In my dream, I had invented this tiny little robot. Basically, it lived in my shoes and whenever I put them on, it would crawl out of a small hole and tie them, no hands necessary. And then it would just crawl back when it was done. And when I wasn't wearing the shoes, it would destroy all the odor-causing bacteria inside. What an amazing robot! It was called--
[SIGHS]
[CHIMES]
--the shoe crab.
EVA: Horseshoe crab?
MARC SANCHEZ: No.
[SIGHS]
[CHIMES]
The shoe crab.
MOLLY BLOOM: That sounds so useful and adorable.
MARC SANCHEZ: Friends, this dream was a wake-up call. I need to build the shoe crab. I mean, I already invented it in my brain. Now I just need to figure out how to make it real. To the tinker table! Don't worry, shoe crab. I shall free you from my mind.
EVA: Good luck, Marc.
MOLLY BLOOM: Wow, that's amazing. We should head to the studio. But first, I need to tell you about this other dream I had. For some reason, I was dressed like a baby from an old cartoon, like, in a onesie and a bonnet and with a pacifier in my mouth. And all around me were tiny Caesar salads. And I just hated the smell.
[THEME MUSIC]
You're listening to "Brains On" from American Public Media. I'm Molly Bloom, and my co-host today is Eva from Fond Du Lac, Wisconsin. Welcome.
EVA: Thanks for having me.
MOLLY BLOOM: So, Eva, what is your favorite robot, real or fictional?
EVA: My favorite robot is probably a real robot named Spot, and he was made-- or it was made-- in Boston Dynamics. And I find it really cool because it can do things such as, like, deliver things. It has its own camera to see things that humans can't. It can help with research. It can open and hold doors for people. And it's, all in general, just fun to watch.
MOLLY BLOOM: That sounds like a very, very cool robot. I've never seen it before. So can you describe what it looks like?
EVA: It's, like, kind of shaped like a dog. It's very yellow. And it walks like a dog too.
MOLLY BLOOM: Wow. What do you think of when you think about robots in general?
EVA: When I think of robots in general, I think of them as, like, mostly helpful. But some people, they do think of them as, like, evil and trying to take over our world and not letting humans do what they usually do. But mostly when I think of robots, I think of them as helpful and they could change our world in the future.
MOLLY BLOOM: Yeah, robots are a lot of fun to think about. And there are so many lovable robots in pop culture, like BB-8 from "Star Wars" or Baymax from "Big Hero Six" or Wall-E.
WALL-E: E-va.
MOLLY BLOOM: He's saying hi to you, Eva.
EVA: Hi, Wall-E.
MOLLY BLOOM: Now, these robots are all the size of animals or humans. But what about robots that are much, much smaller?
EVA: Right. Today's episode was inspired by this question.
GRETA: My name is Greta from Knife River, Minnesota, and my question is what is the smallest robot in existence?
MOLLY BLOOM: Before we get into it, Eva, I just want to ask you how-- when we're talking about tiny robots, how big do you imagine them to be?
EVA: Um, the smallest robot I've worked with is probably about 2 inches. So when I think of tiny robots, my imagination would probably be like so small that I can't see it.
MOLLY BLOOM: Wait, so when you say you've worked with robots, tell me more about that. You've worked with robots?
EVA: Yes, I'm in coding club, so I do a lot of coding and a lot with robots.
MOLLY BLOOM: So when you code robots, what have you been able to make them do?
EVA: So what we've been doing, they're called Ozobots. And we took these special colored markers and we would draw them in some sort of maze or pattern on a piece of paper. And then we put the Ozobots down, which are about 5 inches. And the Ozobot, according to the colors, would move a certain way. And you could coordinate them with a specific color, and you could make it spin, you could make it go really fast, stuff like that.
MOLLY BLOOM: That is so cool. So you know your robots.
EVA: Pretty well.
MOLLY BLOOM: That's awesome. So before we get into the question that Greta asked, which is what is the smallest robot, we need to begin by defining what exactly a robot is. Now, not everyone agrees on the definition 100%, but here's what a lot of people think and the definition that we're working with today.
[MUSIC PLAYING]
EVA: A robot can sense what's going on around them.
MOLLY BLOOM: Decide what to do next.
EVA: And then actually do it.
MOLLY BLOOM: So this means a remote-controlled car is not a robot because you are controlling it with a remote.
EVA: It's not driving itself around.
MOLLY BLOOM: But a real robot car would be programmed to make decisions and drive by itself. It would have what we call artificial intelligence.
EVA: When a machine can make decisions and move on its own, we call that autonomous, or we say it has autonomy.
MOLLY BLOOM: Real robots are autonomous.
EVA: So what's the smallest robot right now?
MOLLY BLOOM: This is tricky to answer. There are a lot of machines out there that are tiny that are being called the world's smallest robot.
EVA: But they can't do much on their own.
MOLLY BLOOM: They can be controlled by magnetic fields or infrared light or even vibrations. And some of them are super-duper tiny. You would need a microscope to see them.
EVA: Which is super cool, but it's closer to a remote-controlled car than one that drives itself.
MOLLY BLOOM: Researchers are working on making them fully autonomous robots but they're not there yet.
EVA: One of the contenders for the title of smallest robot that can do all the things we talked about is the Kilobot.
MOLLY BLOOM: It's about 3 centimeters, or as big as a quarter.
EVA: So why aren't tiny robots even tinier? And why aren't there more of them?
ILLAH NOURBAKHSH: Yes, small robots are hard.
MOLLY BLOOM: That's Illah Nourbakhsh. He's a professor at Carnegie Mellon University in the Robotics Institute. He's also written the books "Robot Futures" and "AI and Humanity."
EVA: He spends a lot of time thinking about robots and the way humans relate to them.
MOLLY BLOOM: And he says there are many reasons why building tiny robots is tricky.
ILLAH NOURBAKHSH: One of them is physics changes when you start making things really small. Things become sticky.
MOLLY BLOOM: You know how a gecko or a spider sticks to a wall? They have tiny hairs on the bottoms of their feet that are attracted to the wall through something called Van der Walls forces.
EVA: Those forces can make tiny robots stick to stuff too.
ILLAH NOURBAKHSH: Suddenly, you're stuck to surfaces that you weren't intending to stick to because you're accidentally kind of suctioning to them.
EVA: And sometimes, instead of being sticky, tiny robots will be slippery.
ILLAH NOURBAKHSH: So if you're trying to get friction down to the ground so your wheels will turn properly, they might just slip because the thing is so light it doesn't really have viscous friction with the ground very well.
MOLLY BLOOM: Another problem is powering the robot with electricity.
ILLAH NOURBAKHSH: And as you make a robot really tiny, you have to make a really tiny battery. And that's both physically difficult because the battery is an actual chemical system, so it's hard to make it small. But it still has a microprocessor, it's still thinking-- whatever the computer version of thinking is-- and that takes a lot of power. And that's going to drain your battery pretty fast.
MOLLY BLOOM: So tiny robots are hard because they can accidentally stick to things or sometimes they slip and slide too much, and it's hard to make batteries teeny enough to power them.
EVA: Plus a lot of equipment and materials you would need to make tiny robots don't necessarily exist yet.
MOLLY BLOOM: But there are indeed some pretty small robots that have some level of autonomy.
EVA: And they have something in common.
MOLLY BLOOM: They were inspired by insects. We asked "Brains On!" producer Menaka Wilhelm to look into that. And, oh, hm-- Menaka, you did more than just look.
MENAKA WILHELM: Of course I did, Molly. I really wanted to understand moving like a bug. So I made these cockroach-inspired shoe covers.
MOLLY BLOOM: Oh, wow.
MENAKA WILHELM: Now I can scuttle. Oh! Please hold still. That sound is too -ish for me. OK, I get it cockroaches are not everybody's thing. But they've managed to solve a lot of the problems you mentioned. They're small. They can move around without too much sticking or slipping, and they do it all without running out of power. So why not try to model tiny robots after cockroaches or other bugs?
MOLLY BLOOM: It makes perfect sense. If nature already figured out a good design for a tiny autonomous thing, why not try to learn from that?
MENAKA WILHELM: Precisely. A lot of scientists are doing just that. And it turns out scuttling like a cockroach is actually a great way for a robot to get around. Kaushik Jayaram is an engineer who has worked on cockroach-inspired mini bots.
KAUSHIK JAYARAM: Cockroaches are excellent at running really fast. They can climb up walls just as easily as they can run on level grounds or along ceilings. They can easily squish into really small gaps. And they are seemingly indestructible.
MENAKA WILHELM: The robot that Kaushik and his team made looks a little like a tiny matchbox with four legs. It can run in different directions, just like an insect. And it's not quite as fast as a real cockroach, but it does have one robo talent that cockroaches don't-- it can run backwards.
EVA: Cool. Also a little icky.
MENAKA WILHELM: Well, here's another insect inspiration that might have a lower ick factor-- the flea. Fleas are master hoppers.
SARAH BERGBREITER: Jumping is kind of nice when you're small because you can handle all of the kind of rough terrain and obstacles that might be in your way.
- Sarah Bergbreiter has worked on a bunch of little bots that spring into the air to move around. One looks a little like a tiny upside-down palm tree. It's about an inch and a half tall with four feet at its base, and its little parts are programmed to press down a tiny spring--
[BOING]
--and then release it to jump into the air.
SARAH BERGBREITER: And this is the way jumping insects work too. So they store energy in a spring and they release that suddenly to get the very high acceleration and high power that they need to jump.
MENAKA WILHELM: Fleas don't use metal springs. They just have springy parts of their legs that work like this. And that's what the flea bot is copying. Eventually, the idea is that the flea bot could jump around or hitch a ride on other beings the way fleas hitch rides on cats and dogs. And besides being small and moving well, bugs are also great at working in groups, which brings us to another insect that's inspired engineers.
FARRELL HELBLING: So you think about bees. They're normally in hives. So how do they work together and how do they work as individuals?
MENAKA WILHELM: Farrell Helbling is a researcher at Harvard. She's working on a little robot called the RoboBee. It's got two wings and four little legs, and it's tiny. These robots weigh 80 milligrams, which is about as much as a postage stamp.
FARRELL HELBLING: They're very, very light. Whenever I hand one to people, they're like, oh, my gosh.
MENAKA WILHELM: And because they're so small, it would be very hard for a RoboBee to do much on its own. But in a big group, or a swarm, small things can be very mighty. Here's Sarah again.
SARAH BERGBREITER: So if you think about the ants in your yard, they can carry off your bag of potato chips if they want to, even though each one is very, very tiny. But if you have enough of them, they can really wreak havoc on your lunch.
EVA: If only we could program RoboBees to stop those ants from stealing our lunches-- now that would be useful.
MENAKA WILHELM: Yeah, leave our lunches out of this. Tiny things can also use that teamwork to build big stuff. Some termite colonies have built nests that are 30 feet high. So other researchers have taken a page from that termite handbook and made little builder bots.
And here's what's really cool about these termite-like robots-- they don't have to talk to each other to work as a team. All the termite bots just have the same goal-- stack blocks to build a structure. And then each individual robot just figures out what it needs to do on its own to make it happen. Pretty amazing.
EVA: Teamwork makes the dream work for people and tiny robots.
MENAKA WILHELM: But at this point, real insects have robo insects beat. They've adapted to survive and move in incredible ways. So before I go, I have to mention that some scientists are trying to add devices to real, live cockroaches so they can move those bugs with remote control. It doesn't work perfectly. One team did it by strapping little bug backpacks onto cockroaches.
MARC SANCHEZ (AS COCKROACH): Oh, cool backpack. Am I headed to school?
MENAKA WILHELM: My cockroach friend, nope. Your backpack is actually a tiny little computer. It's going to tell your legs where to go.
MARC SANCHEZ (AS COCKROACH): What a wild idea.
MENAKA WILHELM: Well, that's time for me to scuttle. Catch you all later.
EVA: Bye, Menaka.
CHORUS: Ba ba ba ba ba ba ba ba ba ba Brains On!
MOLLY BLOOM: Now, before we move on, we have something for you to sense and then react to. It's the--
- Shh.
[OSCILLATING]
Mystery Sound.
[OSCILLATING]
Here it is.
[BOUNCING, VIBRATING]
OK, Eva, what is your guess?
EVA: Maybe it's like a robot that could be like vibrating, like, something vibrating, I feel like, that gets more vibration every single second.
MOLLY BLOOM: Yes, I heard some vibrating noises too. We're going to listen to it again and have another chance to guess in just a bit.
[MUSIC PLAYING]
EVA: If you have a question you want to hear answered on "Brains On!", maybe a mystery sound or drawing to share--
MOLLY BLOOM: Maybe a drawing of Marc's shoe crab, send them to us. Just go to brainson.org/contact.
EVA: That's where we got this question.
ADIA: Namaste. My name is Adia and I'm from La Crosse in Minnesota. My question is why does the sun stay in one place? Can't it move around like Earth?
MOLLY BLOOM: We'll be back with an answer to that during our Moment of Um at the end of the show. Plus, we will read the most recent group of names to be added to the Brain's honor roll.
EVA: So stick around.
[MUSIC PLAYING]
You're listening to "Brains On" from American Public Media. I'm Eva.
MOLLY BLOOM: And I'm Molly. It's time to get back to that mystery sound. And before we listen to it again, I'm just going to tell you that it does not have much to do with robots at all.
EVA: OK.
[BOUNCING, VIBRATING]
It kind of sounds like a bunch of, maybe, like golf balls, like, dumping a bunch of some sort of balls into, like, a cup or something and it's making that vibrating noise.
MOLLY BLOOM: That is a really incredible guess. Here is the answer.
ROWAN: Hi, my name is Rowan, and I'm 6 years old from Toronto. And that was the sound of me dropping a golf ball into a rain gutter pipe.
MOLLY BLOOM: Eva, I am so impressed. That is so incredible. When we chose that, we're like, oh, this sounds so cool, but it seems really hard to guess. But no, you had no trouble. A golf ball in a cup is so close to a golf ball in a rain gutter.
EVA: Um, I lived next to a golf course and I do golf, so--
MOLLY BLOOM: So you have some familiarity with the sound golf balls make in different circumstances.
EVA: Yeah.
MOLLY BLOOM: I love that. Excellent, excellent guess.
[AUDIO LOGO]
There are lots of smart people working on making tiny robots that could help humans and our environment in lots of different ways.
EVA: There are so many possibilities. That's why it's so fun to imagine what the future looks like.
MOLLY BLOOM: And a lot of you have ideas for what you want to see.
PENNY: My name is Penny, and I'm from Bozeman, Montana. And my little robot would be a flying, sword-fighting robot that would fly around you and sword fight the mosquitoes that tried to bite you. And it would sound like this-- [IMITATES SWOOSHING].
ANCHU: Hi, "Brains On!" This is Anchu from Toronto, Ontario, Canada. My tiny robot would be able to brush my teeth for me, and it could do it in two seconds.
VAN: Hi "Brains On!" My name is Van and my robot would clean up all my toys and give me money. And it's sound would be [IMITATES WHOOSHING].
SYDNEY: Hi, my name is Sydney from Boulder, Colorado. And my little robot would clean up my room for me, give me my favorite foods, garden for me, and spray bug spray at any mosquitoes that tried to bite me.
MILAH: My name is Milah, and I'm from Castle Rock, Colorado. My tiny robot would be named Dentobot, and it would clean my teeth so I'd never have to go to the dentist. And the noise it would make would be [IMITATES WHOOSHING].
MOLLY BLOOM: Very creative thinking.
EVA: And some of those are not that far off from what scientists are working on now.
MOLLY BLOOM: There are already tiny robotic sensors that are helping filter the air to make it cleaner and healthier for us to breathe.
EVA: And robot expert Illah Nourbakhsh sees other exciting uses for small robots on the horizon.
MOLLY BLOOM: They could help clean up oil spills or help the environment in other ways.
ILLAH NOURBAKHSH: We use an incredible amount of pesticides in agriculture right now, because we're trying to, in a very broad way, get rid of the wrong species so we can grow the right species to make food. If we can create low-cost robots that can do things like literally weeding so they can physically pull out the problem pests and leave the plants, that changes the game because then we can have much less impact on the climate, much less watershed issues, and still do things like farming.
We have to get help from robotics. So I'm optimistic in the sense that we need solutions to our world's problems, especially climate change. And the only path to those solutions is going to be through really smart, community co-designed technologies. And robotics are going to play an important role in that.
EVA: Other scientists are working on tiny robots that you can wear and even tiny robots that can go inside your body. But those are still in the very early research stages.
MOLLY BLOOM: I wonder what role robots will play in our lives in 20 years or 30 years. It's fun to imagine.
[MUSIC PLAYING]
Another beautiful day at "Brains On!" headquarters. And look, our old friend Eva is here.
EVA: Hello. And this is my daughter, Eva Jr.
EVA JR: Hi.
MARC SANCHEZ: Eva, Eva Jr, I'm so glad you're here. You're just in time. It's been years of hard work, but I'm finally ready to unveil--
[CHIMES]
--the shoe crab.
MOLLY BLOOM: Oh, wow. You finally did it. Amazing.
EVA: What's a shoe crab?
MARC SANCHEZ: It can tie your shoes for you and destroy odor-causing bacteria. Oh, shoe crab.
[MUSIC PLAYING]
MOLLY BLOOM: A true robot can take in information about the world around it, decide what to do with that information, and then do it. That's called autonomy.
EVA: A lot of scientists are working on making small robots, many inspired by insects.
MOLLY BLOOM: There are some challenges in making small robots and how they behave and the parts available to make them.
EVA: But robotic technology could play a big role in solving problems, especially in keeping our environment healthy.
MOLLY BLOOM: That's it for this episode of "Brains On!"
EVA: "Brains On!" is produced by Molly Bloom, Marc Sanchez, Sanden Totten, and Menaka Wilhelm.
MOLLY BLOOM: We had production help from Kristina Lopez and engineering help from Veronica Rodriguez. Special thanks to Tim Lin, the Harvard Microrobotics lab, and Andy Doucettte.
EVA: "Brains On!" is a nonprofit public radio podcast. Your support helps us keep making new episodes.
MOLLY BLOOM: Head to brainson.org/fans to support the show.
EVA: Now, before we go, it's time for our Moment of Um.
[CHORUS OF UMS]
LISTENER: Why does the sun stay in one place? Can't it move around like Earth?
[? BRITTANY KOMAI: ?] That's a really good question. The thing is, it's hard for us to sense how much the sun is actually moving. I'm Brittany [? Komai. ?] I'm a scientist who studies the universe, and I work on building detectors to be able to see out in the universe.
In our solar system, our sun is in the center of it and we're all going around it, the same way in a racetrack then all the cars go around the same center. It's similar with the sun, is that the sun is going slowly around the center of our galaxy. But it's so slow that we don't notice it on Earth.
[MUSIC PLAYING]
So we're on Earth, and Earth is going around the sun. And we looked out, and we realized these tiny little dots were moving around. And those tiny little dots were other planets. And then we were able to put together the picture that all these planets were connected in our solar system.
When we continue to look up and look out, then we can make really, really, really precise measurements of other stars-- and so other stars similar to our sun-- and then you start to see that they're all orbiting around something in the middle. And when you start to work out the path the stars are taking, you find out there's a supermassive black hole. Like, there's a huge, huge, huge black hole. So the sun actually does move, and it moves around a supermassive black hole in the center of the galaxy.
[CHORUS OF UMS]
MOLLY BLOOM: My heart revolves around these listeners. It's the Brain's Honor Roll. These are the talented and brilliant listeners who send us their questions, ideas, mystery sounds, drawings, and high fives.
[LISTING HONOR ROLL]
Thanks.
[MUSIC PLAYING]
We'll be back soon with more answers to your questions.
EVA: Thanks for listening.
Transcription services provided by 3Play Media.
