We are developing soft-bodied robots and there are three important
things to know about these robots. First, their bodies are made
out of soft silicon and they can bend and twist because of that.
They're also inherently safe to be around. Second, because of their
bodies capability to bend and twist, these robots are capable
of very compliant motion and they're also capable of very rapid
agile maneuvers which pushes the envelope on what machines
can do today. And, thirdly, the robots are self-contained and
autonomous; in other words we can package the power source,
the computation and the actuation and sensing needed for these
robots to deliver their motions.
Traditionally soft robots have been either self-contained or capable
of high-performance, but not both. So specifically in our lab we
want to achieve both of those goals simultaneously in one machine.
Currently a soft robot has two parts. One, which is a little bit smaller,
is the rigid part where we store all the supporting hardware.
And the second part, which is a little bit larger, is the soft body
where all the continuous, natural movement happens. And so
when we thought about it, a fish made sense. It has a very similar
structure: in the head of the fish where the brains are held, it is a
little bit more rigid, but in the rear of the fish where the angulatory motion
happens, it's quite soft and compliant.
This is our soft robot fish. Like we said, he has a soft body here in
green and the supporting hardware up front. The way this fish works
is it stores fluid onboard, in the form of a gas, and then releases
this gas through a series of pipes and valves into the body.
If you think about it, it is very similar to blowing up a balloon.
In that case, your mouth would be the pressure source and the
balloon would be the body actuator. And basically by inflating and
un-inflating different parts of of the body we can get it to angulate.
What is special about this fish is it has its brains onboard too.
So if I, from my computer, tell the fish to move forward a signal
is sent wirelessly through the water to the brains and then the brains
tell the hardware what to do in order to move forward.
Biological fish use the 'escape maneuver' or the 'c-turn' to escape
prey and they do these maneuvers very fast; on the order of
100 milliseconds. Our robot fish is also able to execute this escape
maneuver at the same speed: 100 milliseconds.
The fact that our fish can perform an escape maneuver is really
important for the field of soft robotics. It shows that soft robots can
be both self-contained and capable of high performance.
The maneuver is so fast and it has got such high body curvature
that it shows soft robots might be more capable than hard robots
in some tasks.
