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Researchers use tough sea slug muscles to build a biohybrid robot

Researchers use tough sea slug muscles to build a biohybrid robot


The bot can crawl like a turtle, but it's slower than a slug

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We're a long way from building the half-human, half-machine cyborgs of science fiction, but we are taking small (very slow) steps in that direction. Case in point is this biohybrid robot from Case Western Reserve University. It uses muscles taken from the mouth of a sea slug connected to 3D-printed components to move about, and — when an external electrical current is applied to force the muscles to contract — can 'walk' at the extremely unhurried pace of 0.43 centimeters a minute in a form of locomotion similar to a turtle crawling up a beach.

"We're building a living machine."

The scientists who designed the bot say that in the future, groups of these creations could be used for lengthy missions which would tire traditional robots. Using muscle cells instead of mechanical parts means that semi-organic bots can get energy from their natural environment — just like animals do. "We're building a living machine — a biohybrid robot that's not completely organic, yet," said Western Reserve PhD student Victoria Webster in a press statement. The organic nature of the bots also mean that they could be discarded use, left to degrade without damaging the environment.

A Californian sea hare releasing ink. (Image credit: Genny Anderson /

The biohybrid bot uses muscle cells taken from around the mouth of the Aplysia californica, a sea slug also known as the Californian sea hare. The researchers chose to use material from the californica because the animal is known for its toughness. The sea hare can survive in a variety of temperatures and water salinity, and is at home in both deep ocean water and shallow pools. "We're creating a robot that can manage different tasks than an animal or a purely manmade robot could," said Roger Quinn, director of Case Western Reserve's Biologically Inspired Robotics Laboratory.

At this point in time, though, Case Western's bot is not up to any tasks beyond limping slowly around. The researchers used an electrical current to stimulate the borrowed sea slug muscles, but even at its current slow pace its movements cannot be directed. Deploying organic muscle in robots like this has a lot of advantages, but a control system is also needed before the bots can be much use. The next step, say researchers, is to incorporate the sea slug's neurons and nerves as well, to like an organic controller.