Soft robots go swimming
A new robotic fish can wiggle and writhe like the real thing
SUITING UP Building robotic fish (one shown), may give researchers a way to sneak into groups of fish and track the schools' behaviors.
Both: M. Scott Brauer
A new robotic fish can wiggle and writhe like the real thing. With a squishy silicone body and a bellyful of electronics, the little swimmer flips and turns nearly as fast as living fish do. 
To make the robot so nimble, MIT engineers sandwiched a firm plastic sheet between hollow channels embedded in each side of the tail. Spurts of gas inflate the channels on one side, which push against the plastic sheet to bend the tail.
Using a small canister of compressed carbon dioxide tucked in the fish’s guts, researchers can make the bot swim forward, or contort its body to quickly change direction. They can also control the angle and speed of the fish’s twists, Daniela Rus and colleagues report in the March Soft Robotics. Such an agile gizmo could sneak into fish schools and collect behavior data, the researchers suggest. Building bots based on living and extinct animals could also help to study fish evolution (SN: 6/2/12, p. 30).
WIGGLE AWAY Soft-bodied robot fish swim and perform acrobatic maneuvers as MIT researchers explain how they work. Credit: MIT
