The team at Berkeley Lab was able to create the tiny system with the aid of a compound called vanadium dioxide, which rapidly changes from an insulator to a conductive metal at 67 degrees. In making its transition, the compound rapidly contracts, making it possible to mimic a muscle in torsion. The artificial micro-muscle performed impressively in tests, able to propel objects up to 50 times heavier than itself more than five times its length within just 60 milliseconds.
See the micro-muscle in action below, in a video created at the Berkeley Lab:
The muscle itself responds best to direct heating, which lets scientists select which micro-muscle system to activate at any one time. Researchers at the lab believe that this selectiveness could, in time, make vanadium dioxide the key to creating an artificial neuromuscular system, creating muscle-like motors that can support weight and are flexible enough to perform in small spaces on low energy.