The researchers fabricated a tightly coiled nickel-titanium wire and wound it around the mesh tube, mimicking the circular muscle fibers of the earthworm. They then 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. Kim and his colleagues developed algorithms to carefully control the wire's heating and cooling, directing the worm to move in various patterns.
The group also outfitted the robot with wires running along its length, similar to an earthworm's longitudinal muscle fibers. When heated, an individual wire will contract, pulling the worm left or right.
As an ultimate test of soft robotics, the group subjected the robot to multiple blows with a hammer, even stepping on the robot to check its durability. Despite the violent impacts, the robot survived, crawling away intact.
"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."
'/>"/>
| Contact: Sarah McDonnell s_mcd@mit.edu 617-253-8923 Massachusetts Institute of Technology Source:Eurekalert |