Autonomous soft-robot is as swift as a fish

The self-contained autonomous soft robot, claimed to be the first of its kind, is detailed in a paper published in Soft Robotics.

The robotic fish was built by Andrew Marchese, a graduate student in MIT’s Department of Electrical Engineering and Computer Science and lead author of the paper.

Each side of the fish’s tail is bored through with a long, tightly undulating channel. Carbon dioxide released from a canister in the fish’s abdomen causes the channel to inflate, bending the tail in the opposite direction.

According to MIT, each half of the fish tail has two control parameters: the diameter of the nozzle that releases gas into the channel, and the amount of time it’s left open.

In experiments, Marchese found that the angle at which the fish changes direction is almost entirely determined by the duration of inflation, while its speed is almost entirely determined by the nozzle diameter. That decoupling of the two parameters is something that biologists had observed in real fish, he said.