MIT builds a tiny robot that swims with living muscle cells

The robot is a gel frame about the size of a stick of gum with two fins. Each is coated in muscle cells thinner than a hair, engineered to contract when hit by light.

Top speed

4 body lengths a minute

At top speed the robot swims about four body lengths a minute, far slower than an Olympic swimmer's 65.

Researchers say muscle-powered swimmers could one day monitor fragile aquatic environments. Their next goal is a body design that swims faster.