Robot that uses living muscle tissue

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)