Powered by muscle cells, a paper-thin robot swims through watery maze

MIT engineers have developed a paper-thin robot, powered by muscle cells, that can swim through water. The robot's "skeleton" is a gel film, about the size of a stick of gum, with two halves forming fins. The fins are covered with thin, genetically-engineered muscle cells that respond to light. By shining light on one fin or the other, the researchers can control the robot's direction and speed.

The team demonstrated the robot's ability to navigate a simple watery maze and swim a distance four times its body length in a minute. While this speed is slower than that of Olympic swimmers, it's comparable to that of a cow shark. The robot's slim design and muscle-powered movement make it potentially cheaper and more efficient than bulky, 3D biohybrid robots.

The technology could enable delicate jobs like exploring environments too fragile or unpredictable for conventional hardware.