Soft robot mimics earthworm movement

U.S. researchers say they've developed a "soft" robot that inches along like an earthworm and can keep working even after taking a pounding from a hammer. Scientists at the Massachusetts Institute of Technology, Harvard University and Seoul National University have engineered a soft autonomous robot that moves across surfaces by contracting segments of its body, a process called peristalsis. Such a soft robot could be useful for navigating rough terrain or squeezing through tight spaces, MIT mechanical engineering Professor Sangae Kim said. The robot is named "Meshworm" for the flexible, meshlike tube that makes up its body that contains "artificial muscle" in the form of wires made of nickel and titanium -- a shape-memory alloy that stretches and contracts with heat. A small current applied to segments of the wire causes a squeezing the mesh tube, propelling the robot forward. The robot is extremely resilient, researchers said, and can survive being stepped on or even hit with a hammer. "You can throw it, and it won't collapse," Kim says. "Most mechanical parts are rigid and fragile at small scale, but the parts in Meshworms are all fibrous and flexible. The muscles are soft, and the body is soft ... we're starting to show some body-morphing capability."