Earthworms creep along the ground by alternately squeezing and stretching muscles along the length of their bodies, inching forward with each wave of contractions. Snails and sea cucumbers also use this mechanism, called peristalsis, to get around, and our own gastrointestinal tracts operate by a similar action, squeezing muscles along the esophagus to push food to the stomach.
Now researchers at MIT, Harvard University and Seoul National University have engineered a soft autonomous robot that moves via peristalsis, crawling across surfaces by contracting segments of its body, much like an earthworm. The robot, made almost entirely of soft materials, is remarkably resilient: 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.
Researchers created the “artificial muscle” using nickel and titanium, producing a soft, flexible, mesh-like tube that stretches and contracts with heat.
Perhaps the most remarkable thing about Meshworm is its ability to withstand some pretty rough treatment. Clobber most robots with a hammer and it will likely result in some sparks, puffs of smoke and a major malfunction. Clobber Meshworm and it just continues crawling along as if nothing’s happened – as demonstrated in the video below. It can also survive someone stepping on it.
has the ability to survive a frightening degree of misuse, and that
provides one clue into DARPA’s interest in the new technology.
described by writer Jennifer Chu, the field of soft robotics is of
growing interest to engineers. With little or no need for bulky
hardware, soft robots are more durable and lend themselves to
miniaturization more easily than their mechanical counterparts.
terms of military purpose, soft robots like Meshworm could be
air-dropped, launched or thrown over relatively long distances, land
without damage, and set about crawling silently around, squeezing
through tight openings and conducting surveillance.
The Meshworm uses peristalsis, contracting and expanding different muscle segments, to inch across the ground. Image via MIT
But there might well be more benign uses as well. Kellar Autumn, a professor at Lewis and Clark College who studies biomechanics in robotics, told MIT that devices similar to the Meshworm could someday be useful for a wide range of applications, including both consumer technology and medical devices such endoscopes, implants and prosthetics. “Even though the robot’s body is much simpler than a real worm—it has only a few segments—it appears to have quite impressive performance,” Autumn said. “I predict that in the next decade we will see shape-changing artificial muscles in many products, such as mobile phones, portable computers and automobiles.”