The Meshworm is a robot that moves via peristalsis, crawling across surfaces by contracting segments of its body, much like an earthworm. Sangbae Kim, the Esther and Harold E. Edgerton Assistant Professor of Mechanical Engineering at MIT, says such a soft robot may be useful for navigating rough terrain or squeezing through tight spaces, according to MIT news.
The Meshworm was named for the flexible, meshlike tube that makes up its body. The shell is so resilient that it that went unscathed even after scientists stepped on it and bludgeoned it with a hammer. The pliable exterior also makes them safe for human interaction. In addition to its resilience and maneuvering capabilities, the Meshworm creeps silently, one quarter inch at a time.
For decades, roboticists have looked for ways to create soft-shelled robots but they could not find a way to power the robot without limiting its pliability and increasing its breakability.
Scientists used nickel titanium, a shape-memory alloy that stretches and contracts with heat, to create “artificial muscle.” Recreating an earthworm’s circular and longitudinal muscle structure, the researchers first made a long, tubular body by rolling up and heat-sealing a sheet of polymer mesh. The mesh, made from interlacing polymer fibers, allows the tube to stretch and contract, similar to a spring.
The scientists wound wire around tube, creating segments along its length. They then applied a small current to the segments of wire, squeezing the mesh tube and propelling the robot forward.
The possible gonvernmental uses of the Meshworm are still to be determined. The robot’s ability to travel silently where it is impossible or impractical for people or hard objects makes it an obvious tool for reconnaissance, surveillance, and exploration.
Transporting objects, even small ones, inside the small Meshworm could be challenging, however, as demonstrated by the difficulty roboticists had in constructing a soft-shelled robot. Placing hard objects inside the robot will limit is pliability, though the robot’s resilient soft shell and slow-moving pace will keep the inserted objects relatively safe. Such objects will be limited by size or pliability.
The Meshworm invention may also be a boon for healthcare. Researchers say the Meshworm may be useful for next generation endoscopes, implants, and prosthetics.
The details of the design are published in the journal IEEE/ASME Transactions on Mechatronics.