Engineers Develop Flexible Robot with Earthworm like Movement
Taking inspiration from nature once again, the researchers at the Massachusetts Institute of Technology have developed a earthworm like robot called 'Meshworm' that is developed from soft materials into a meshlike tube that crawls across surfaces by contracting segments of its body, much like an earthworm. What is different in this is that, even when stepped upon or bludgeoned with a hammer, the robot is able to inch away, unscathed.
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."
This unique creation grabs its name 'Meshworm' from its flexible meshlike tube that makes up its body. Researchers created "artificial muscle" from wire made of nickel and titanium -- a shape-memory alloy that stretches and contracts with heat. They wound the wire around the tube, creating segments along its length, much like the segments of an earthworm. They then applied a small current to the segments of wire, squeezing the mesh tube and propelling the robot forward.
The new findings were published in the journal IEEE/ASME Transactions on Mechatronics.
Kim and his colleagues carefully looked at the earthworm for deign guidance. They observed how the creepy crawler r is made up of two main muscle groups: circular muscle fibers that wrap around the worm's tubelike body, and longitudinal muscle fibers that run along its length. Both muscle groups work together to inch the worm along.
The researchers fitted a small battery and circuit board within the tube, generating a current to heat the wire at certain segments along the body: As a segment reaches a certain temperature, the wire contracts around the body, squeezing the tube and propelling the robot forward.
"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."
Besides Kim, other co-authors are graduate student Sangok Seok and post-doctoral researcher Cagdas Denizel Ona, MIT; associate professor Robert J. Wood, Harvard University; assistant professor Kyu-Jin Cho, Seoul National University, and Daniela Rus, professor of computer science and engineering at MIT.