Powerful New Torsional Micro-Motor Made from Vanadium Dioxide

Highly valued by the electronics industry, vanadium dioxide is an insulator at low temperatures but abruptly becomes a conductor at 67 degrees Celsius. This temperature-driven phase transition from insulator-to-metal is expected to one day yield faster, more energy-efficient electronic and optical devices. It is also an ideal candidate material for creating miniaturized, multi-functional motors and artificial muscles. Berkeley Lab researchers have now demonstrated a vanadium dioxide-based robotic torsional muscle/motor that for its size is a thousand times more powerful than a human muscle. "We've created a micro-bimorph dual coil that functions as a powerful torsional muscle, driven thermally or electro-thermally by the phase transition of vanadium dioxide," says physicist Junqiao Wu. "We achieve superior performance in power density and speed over the motors and actuators now used in integrated micro-systems." This video clip shows the micro-muscle functioning first in micro-catapult mode, throwing out an object, and then in micro-explosion mode, sensing a proximate object and reacting by pushing the object away.