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

Swimming can take a lot of muscle. But as MIT engineers have found, even a single layer of muscle cells can power through water if designed right. In a paper appearing today in the journal, the team presents a design for a thin, muscle-powered swimming robot. The "skeleton" of the aquabot is made from a film of gel that is about the length and width of a stick of gum. Each fin is covered with a layer of live muscle cells that is much thinner than a single strand of hair.