Artificial muscle tissue might sound like the work of science fiction, but that may not be the case anymore. As described in a recent paper in Advanced Intelligent Systems, researchers outline the specifications for a prototype material made entirely of a natural protein, elastin, that can simulate the contractive qualities of biological muscle tissue.
Elastin is a commonly occurring protein in the human body that lends elasticity to crucial areas of the body, including blood vessels. The research team, out of the University of Freiburg, developed two different elastin-based materials: one that responds to pH changes, and the other that responds to temperature changes. Researchers then created a two-layered material using these two different elastin-based tissues, which could allow for the shaping of the material and control over its movement.
To test the material, researchers exposed the materials to a cycle of pH changes, converting energy to mechanical energy that enabled the material to perform its own contractions in a regular cycle. Replicating contractions allows the material to replicate the activity of biological muscular tissue. In so doing, researchers also developed a basic programming for the muscle to “learn” and “forget,” reinforcing the contraction process.
Attempts to make synthetic muscle tissue are not new. Many efforts have been made in the past, including the development of tissue that could power actual robots. The protein muscle developed at the University of Freiburg differs from other attempts at artificial muscles because of its bio-based composition and its ability to operate entirely on chemical energy, rather than with the help of a machine. The material is powered with sodium sulfite.
While acknowledging their muscle tissue is still a prototype, the research team is already focusing on the range of possible applications for their tissue: prosthetics, robotics, medicine, and more. They also hope that they could find other ways to power the tissue, including salt in a given environment.