Researchers have developed a tiny robotic muscle that’s 1,000 time stronger than a human muscle.
The team of researchers at the University of California-Berkeley found that vanadium dioxide changes from an insulator to a conductive metal at about 152 degrees, which produced a huge amount of strength during the transition.
The scientists used the material to demonstrate a microchip-sized, twisting robotic motor that could catapult objects 50 times heavier than itself over a distance five times longer than itself faster than the blink of an eye – within 60 milliseconds.
The team fabricated the micro-muscle from a long V-shaped ribbon made of chromium and vanadium dioxide, which is already prized for its ability to change size, shape and physical identity, and heated it with a tiny pad or by electrical current.
When the dual coil formed by the ribbon is heated, said physicist Junqiao Wu, who led the team, it turns into either a tiny catapult or a proximity sensor, which causes a rapid change in the muscle’s resistance and shape that pushes away nearby objects.
“Multiple micro-muscles can be assembled into a micro-robotic system that simulates an active neuromuscular system,” Wu said. “The naturally combined functions of proximity sensing and torsional motion allow the device to remotely detect a target and respond by reconfiguring itself to a different shape. This simulates living bodies where neurons sense and deliver stimuli to the muscles and the muscles provide motion.”
The team found the micro-muscles could twist and turn more than 1 million times without degradation, and they showed far greater movement abilities than current robotic motors.
Vanadium dioxide can also absorb light and convert it to heat, which will allow the micro-muscle to be triggered optothermally.
The technology could eventually be used to build a complex organism that simulates an active neuromuscular system, perhaps in prosthetic limbs or surgical procedures.
“With its combination of power and multi-functionality, our micro-muscle shows great potential for applications that require a high level of functionality integration in a small space,” Wu said.