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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.
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