By combining the mouth muscle from a sea slug with 3D-printed components, researchers have managed to build a biohybrid robot that is able to crawl not unlike a turtle crossing a beach. The mixture of living tissue and man-made parts is a sector moving into its own, and it is hoped that this particular roboslug could have applications in searching tasks at the bottom of the ocean.
“We're building a living machine – a biohybrid robot that's not completely organic – yet,” says Victoria Webster, a PhD student who is leading the research. The muscle from the sea slug is controlled by an external electric field, which should mean that in the future scores of the roboslugs could be released to carry out tasks such as locating toxic leaks or even searching the ocean floor for black box data recorders from crashed planes, outlasting conventional robots that would run out of battery before the task is complete.
This latest biohybrid robot comes hot on the heels of the robo-ray unveiled earlier this month. That creation used a sheet of laser-sensitive rat heart muscle cells overlaid on a silicon and gold skeleton, so that as the cells were stimulated by the laser, they contracted in a wave along the body of the "stingray", making it propel itself forward. In order to keep the heart cells alive, it had to be placed in a special solution, something that the creators of the robot sea slug hope they can overcome.
The California sea slug, from which the mouth muscle is taken, can naturally withstand substantial changes in temperature, salinity, and other variables as they are buffeted around the Pacific Ocean tides, moving between shallow coastal waters and deep water environments. This means that while bird and mammal cells require strict conditions in which to work, the sea slug cells are far more adaptable, and crucially are still durable down to cell level.
The aim is to make a device that is able to perform different tasks than only a robot or animal can currently do, making it more flexible than either on its own. The use of muscle cells allows the biohybrid robots to be flexible, and the arrangement of muscle cells taken from the slugs' mouths happened to be just perfect for what the researchers needed. The roboslug has two “arms”, and moves when the muscle contracts and swings each arm back and forth.
In the future, the researchers hope to integrate collagen from the slugs' skin to build the scaffolding for the biohybrid, as well as include bundles of neurons and nerves as an organic controller for the muscles.