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[♪ INTRO].

When designing robots, engineers  often look to nature for inspiration. That’s because evolution has  done a pretty incredible job of creating some ingenious designs.

And that’s definitely true with the latest  craze in engineering: designing tiny robots. We’re talking robots that are so small  they can go where no bot has gone before… like inside the human body. And such itty bitty bots need miniature  muses — which is why engineers are looking to some of the smallest  organisms on the planet for design tips.

This first itty bitty bot is a free-swimming robot that can accomplish a lot more than you’d think. To achieve what no teeny bot has  before, researchers modeled it after a lifestage of jellyfish: the ephyra: the  very first free-swimming form of a jelly. Since their bells aren’t fully formed,  ephyrae have eight little structures known as lappets that beat up and down to  propel themselves through the water.

And the bot version looks and swims just like one. It’s a mere three millimeters in  diameter and has eight bendable flaps that beat at a frequency of  around 150 times a minute. Engineers chose this design  specifically because of how well baby jellies move about in the ocean.

You see, water is much more viscous to a  tiny creature than a big one like ourselves, so moving through it becomes a lot harder. But the rapid movement of these eight  little flaps mix the water around them, making little currents that propel the animals and the bot they inspired through the water. That’s especially important given engineers hope to have these bots swim about inside people.

And our bodily fluids can be pretty thick! What’s even cooler, though, is that each  little flap on the bot has a magnetic microparticle at the end which allows  researchers to steer it using magnetic fields. This little bot can burrow  into a pile of glass beads or use its flaps to pick one  up and carry it as it swims.

Researchers hope to use these features  to deliver drugs inside the human body in a targeted way, such as directly to a tumor. Plus, the currents it makes could mix chemicals  at the site to ensure the delivery of a specific concentration of medicine  over a long period of time. This jelly-inspired bot is not  quite ready for in-body use yet.

Its designers are still tweaking the materials  and considering ditching the magnetic field-directed movement in favor of an  on-board system… like living muscle cells. But regardless of what the  future holds for this bot, the current version teaches us more  about the ephyrae in our ocean! And they play an important role  in mixing the water around them, and bots like this could help researchers  figure out how that mixing may change as our oceans continue to warm.

The next robot is unique in that it can  move through almost any type of environment you put it in: land, water,  or even your digestive system! The roughly 3.5 millimeter-long bot  might look like a tiny rubbery strip. But it moves like a little caterpillar…  and swims like a jellyfish!

The designers of the baby jelly bot  are responsible for this one as well, and they say that they were inspired  by lots of soft bodied creatures because of the way these animals  navigate complex environments. Much like the jelly bot, this caterpillar-esque  robot is controlled with magnetic fields and can move through liquids with ease  by generating helpful water currents. But it can move in other ways too.

Like,  it can walk, it can jump, it can crawl! And since it can move through  water and on dry surfaces, its engineers envision a lot  of different applications. The current version could wiggle about  inside your digestive or urinary tracts.

But researchers hope to make smaller  iterations that could navigate anywhere in our bodies, no matter how wet  — places that current technologies like catheters and laparoscopic  devices can’t access. The designers even think they can  manufacture future versions of this and the ephyra bot out of biodegradable  materials that would break down and be excreted after a few months. So, there’d be no need to remove the  bots after they perform their tasks.

And already, this little pseudo-caterpillar  is helping researchers better understand the locomotion of the small,  soft-bodied creatures that inspired it. RoBeetle is one of the smallest,  strongest independent bots ever made. This beetle-inspired robot weighs  about the same as three grains of rice, but it can carry items up to 2.6 times  heavier thanks to microscopic wires that act like muscles and a teeny  tiny fuel tank filled with methanol.

This alternative fuel source  is the real innovation. Most other bots have to connect to external power, but methanol allows RoBeetle  to be small and independent. Methanol reacts with oxygen and a platinum  coating on the wires inside the beetle in an energy-releasing reaction  called catalytic combustion.

The heat generated by this reaction causes  the wires in the bot’s body to contract; then, they expand when they get cool. That allows RoBeetle to move forward,  trundling along like a real beetle does! This methanol system is also much  lighter than a traditional battery.

Even when its fuel tank is totally full, the entire robot tips the  scales at a mere 183 milligrams. Plus, the methanol system is more powerful. The combustion reaction generates up to  20 megajoules of energy per kilogram of methanol, which is over 10 times  more power than small batteries.

And it lasts longer! RoBeetle  can wander for over an hour and even tackle steep inclines. If it were powered by batteries, it would only be able to  move about for a few seconds.

RoBeetle is able to go places that  other robots and humans can’t — like really tight spaces. So one day something like it could be used to help with search and rescue operations. And RoBeetle is already revealing  the secrets of actual beetles.

In the process of designing  this tiny but mighty bot, researchers have gained a better  understanding of beetle locomotion as well as their ability to carry  loads much heavier than themselves. Unfortunately RoBeetle is currently unsteerable, which means it can only travel,  like, straight forward in a line. So, they’re going to need to figure out steering.

And they hope to add wings, too, to make  it the smallest untethered flying robot. If RoBeetle does get off the ground, it’ll have some competition for the  title of smallest flyer, though. The RoboBee X-Wing is the current record-holder for the lightest independent flying bot.

Its four little wings are just 3.5  centimeters across, and in total, RoboBee weighs only 259 milligrams. Now, I know what you’re thinking:  that doesn’t look like a bee, it looks more like a dragonfly. That’s because, despite the name, its designers actually drew  inspiration from a few flying insects.

The wings were definitely  modeled after a dragonfly’s. But it can lift itself up into the air by  beating its four wings 170 times per second — which is more like a bee’s  powerful and efficient takeoff. Creating a tiny flying bot that’s not  connected to an external power source has been a challenge for engineers.

Typically, heavier-than-air  flight requires a lot of power, and existing power storage capabilities  quickly make a tiny robot very heavy. But the designers of RoboBee  figured out how to power it using six teeny tiny solar panels  each weighing just ten milligrams. The panels generate a current  which powers two actuators.

These essentially “contract”  like muscles when that current passes through them, thus moving the wings. And it’s very efficient. The bot only  consumes 110 to 120 milliwatts of energy when flying — 100 times less  power than an LED light bulb.

Unfortunately, right now, RoboBee only  works in the lab…because it requires three times more light to power it  than your typical sunlit environment. Maybe these engineers should  consider recombining forces with the RoBeetle designers! One way or another, researchers hope  to improve on the design so that,.

Someday, we can use similar bots  to move through small spaces or monitor sensitive environments. After all, since they’re so light, they  could land on a leaf and quietly observe the ecosystem — something that  currently available drones cannot do. All they need a tiny, super-lightweight camera and a sun that’s three times  more powerful than ours.

But they are also already  teaching us about living things. In designing these little flying bots,  engineers made a significant breakthrough in the field of tiny robotics and increased our  understanding of how insects actually fly. AntBot is the first walking robot that  can explore its environment randomly and go home automatically — no GPS required!

Now, despite the name, it’s a  giant compared to the other robots. I’ve talked about so far:  a whopping 2.3 kilograms. But it was modeled after tiny desert ants!

That’s because these ants  are fantastic navigators. They can find their way around without the help of the chemical pheromones  that other ant species use. In the hot desert environment  where these ants live, such pheromones would immediately evaporate.

So instead, they use the sun to guide them. They get their heading by looking  at the pattern of polarization. Now light is considered totally polarized when all the light waves  align along the same plane.

And it just so happens that the sun’s  rays get filtered by our atmosphere in such a way that the light at about a 90  angle from the sun is the most polarized. So, by being able to detect this  polarization, as well as the sun’s position, the ants can use sunlight as a kind of compass. And they’re most sensitive to UV light,  which is visible even on a cloudy day.

So they get a pretty accurate heading  no matter what the weather looks like. The sun also helps them determine  how far they go in each direction. Distance is measured by counting  steps — yes, ants can count! — and by observing their  movement relative to the sun.

All in all, that’s some fancy  navigating for a little ant! And it’s what researchers  decided to mimic with AntBot. The robot has an optical  compass which, like the ants, uses the sun’s polarized light  to determine the bot’s heading.

AntBot also directs an optical  movement sensor at the sun to measure the distance it covers as  it travels. And it is very precise. The bot can measure its heading with  0.4 degrees of precision, even in cloudy weather, and it’s able to return to within 1  centimeter of its original starting location.

Unfortunately, since it relies on the  sun being in the sky for navigation, more work is needed to make AntBot useful 247. Even so, this new technology may  end up making navigation cheaper and more precise in autonomous  vehicles and robots in general. And designing this current  version taught researchers a lot about the navigational  abilities of these desert ants, which is a valuable contribution  to science in and of itself!

From jellyfish to ants, tiny creatures have helped inspire engineers to create  a fleet of mini robots! While the current models  all have their limitations, they’re pretty impressive for prototypes. They’re already breaking  technological and size barriers — imagine what the future holds!

And not only are these bots advancing robotics, they’ve also given the scientific  community a deeper understanding of the locomotion, navigation, and overall biology of the creatures they’ve been modeled after. So, they’re helping us understand  the planet’s littlest lifeforms, too. Thanks for watching this episode of SciShow!

Before I go, I want to remind  you that time is running out for the SciShow pin of the month! This month’s design highlights the  International Ultraviolet Explorer, a hardworking space telescope that  launched in 1978 and continued to work 24 hours a day, 7 days a week for almost 19 years! What a trooper!

And you can celebrate it with us. Unlike the IUE, the pin is only  around for a very short time. So if you want this stylish tribute, be sure  to place your order before February 1st!

You can find it by searching SciShow pin  at DFTBA.com, or in the merch shelf below. [♪ OUTRO].