"If you don't have legs, you can propel yourself by deforming your body. Earthworms do this through peristaltic locomotion: The muscles in one body segment contract while others relax, which creates a traveling wave that moves them forward. Our robot, Meshworm, moves this way, using wires for muscles. To make a muscle segment, we twist the wire into a long, narrow spring, and then wrap the spring into a tube shape. After that, we link up several segments and cover them with plastic braided mesh, like the screen on your window.