Hi I'm Kate the simple biologist and today we're going to be talking about robots
We're pretty used to seeing robots in our daily lives like rumbas Furbies
or hands-free car washes
but these are all clearly mechanical. They're made of metal and they run on
electricity, but what about robots printed from life. Today we're going to
be talking about a paper that brought together researchers from Harvard
Sogang University and Stanford and what these researchers created was a new biohybrid soft robot
Part of the reason the robot these researchers build is so special is
that it's in two different fields. The first field is called soft robotics
meaning that the robot is made from soft materials like fabric rubber or silicone
rather than harder more inflexible materials like metal or hard plastic
The other special thing about this robot is how it's powered. Instead of using
batteries, it uses biology. Real living cells are used power this robot which is why
it has the name biohybrid. So now we know that these researchers built a
biohybrid soft robot but what does it look like and what does it do?
The researchers wanted to mimic something that you find in real life and
so what they chose to mimic was a stingray. They wanted their robotic
stingray to be able to recognize light and swim towards it all while being
about the size of a penny
So how do you go about building a robot that swims like a sting ray?
The answer is that you go to the source and look at how stingrays themselves swim
What you'll find if you look at the stingrays is that they really need five different layers
to be able to swim. From top to bottom they need a layer of skin, a layer of muscle,
a skeleton, and then another layer of muscle and another layer of skin.
But if we think about making a robot they don't really need skin so the most
important things to care about are the two layers of muscle and the skeleton.
But when it comes to robotics it's much easier to build one layer of muscle than two.
The stingrays themselves need two layers of muscle because when they swim
they do this undulation motion.
One layer of muscle is required to pull the fin up and another
layer is required to pull it down leading to that smooth flowing motion
So how are we going to create a tiny robot that does all the work of two layers of
muscle and a skeleton in a real stingray? The first thing needed for this robot is
a body, and these researchers chose a type of silicone found in everything from
contact lenses to shampoo called dimethicone. Attached to the silicone body
is a golden skeleton chosen for its chemical inertness and for how light it is.
Next is another small layer of silicone and then finally the power of
the whole stingray - a layer of printed muscle tissue and the cells of this
muscle tissue are rat heart cells! These researchers were able to get away with
one layer of printed muscle tissue instead of two because they engineered
the gold skeleton to spring back up after it was pulled down by the muscle tissue
kind of simulating the second layer of muscle without it actually having to be there
making the overall design a lot more simplistic and a lot more likely to work
So now we have a robot with a body, a skeleton, and a power source in the
form of muscle tissue. But how do you make it swim correctly with that smooth
undulation motion?
And how do you make it swim correctly only in response to light?
The way you have the robot respond to light is by creating a patch of specialized cells at
the front of the ray. Those cells are able to sense light, and when they sense
light, they contract. And not only do they contract, they then tell the cells next
to them that they should contract too. And then those cells tell their neighbors
and so on and so forth. So all of the muscle cells in the ray end up
contracting and pulling the fin down in response to light.
The researchers also wanted the ray to be able to turn and to do that you need
each fin to operate separately and so you need two patches of light sensitive cells
the message to contract will then come from those light-sensitive cells
and move in a wave down each fin of the ray
All in all the ray used about 200,000 cells to move. That's 200,000 cells in
a ray about the size of a penny! and it was about the weight of a penny sized
piece of paper! It could also swim left or right depending on where the light
was placed. The side with more light will contract more frequently so kind of like
paddling on one side of a canoe more, you turn in that direction.
This robotic Ray has outperformed all other kind of biohybrid soft robots being able to
go faster, travel further, and outlast any other robot created. Right now this
ray can only work in a specialized salt solution with plenty of sugar to feed
the living muscle tissue, but maybe in the future these biohybrid soft robots
could function in the actual ocean. And right now this robot can only respond to
light, but maybe in the future it can respond to nutrients or maybe even sound
I don't know what's next for this field of robotics, but I know that this is only the beginning.
I hope you enjoyed this video feel free to subscribe to my
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more science updates @simplebiologist See you next time!