This "biohybrid" robotic finger melds a robotic skeleton with living rat muscle. The device is inside a container of water to keep the muscles from withering. The research is on the cover of this week's issue of the journal Science Robotics. Video below. From National Geographic:
“If we can combine more of these muscles into a single device, we should be able to reproduce the complex muscular interplay that allows hands, arms, and other parts of the body to function,” says study author Shoji Takeuchi, a mechanical engineer at the University of Tokyo. “Although this is just a preliminary result, our approach might be a great step toward the construction of a more complex biohybrid system.”
The research group began looking at living muscle tissue because plastic and metal provided a limited range of movement and flexibility. To grow their robot's muscles, they layered hydrogel sheets filled with myoblasts—rat muscle cells—on a robotic skeleton. The grown muscle is then stimulated with an electric current that forces it to contract.
"Biohybrid robot powered by an antagonistic pair of skeletal muscle tissues" (Science Robotics)
Japanese engineers integrate living muscles into robots.— China Xinhua News (@XHNews) May 30, 2018
The robots can mimic actions of human finger https://t.co/r5CeluR0Ss
(Video courtesy of 2018 Shoji Takeuchi, Institute of Industrial Science, the University of Tokyo) pic.twitter.com/gmCizoYwFh