A schematic for Berkeley Lab's new torsion muscle Care of the DOE's Lawrence Berkeley National Laboratory

Scientists have created what may become the future of prosthetics, a robot “muscle” that can throw something 50 times its own weight five times its length in a surprisingly fast 60 milliseconds. While it’s easy to envision what this means for the future, a Hollywood image of robot arms crushing steel bars with ease comes quickly to mind, don’t fear just yet, the new muscle is currently the size of a microchip.

“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,” said Junqiao Wu, the project’s lead scientist at the U.S. Department of Energy’s Lawrence Berkeley National Labs (Berkeley Labs).

The strength of the new robotic muscle comes from the special property that vanadium dioxide possesses. VO2 changes physical state when heated or cooled. The muscle, coincidentally in the shape of a V, is heated causing one dimension to contract while the other two dimensions expand, creating a torsion spring. Think catapult, but on a much smaller scale.

While in its current state the muscle demonstrates the potential for what may be the future of artificial neuromuscular systems. Wu’s device functions in a way that creates a proximity sensor, which is very similar to the way biological muscles work. This torsion spring and proximity sensor features “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,” according to Wu.

The micro-muscle requires a way of heating to actuate. As it stands, Wu thinks “electric current is the better way to go because it allows for the selective heating of individual micro-muscles and the heating and cooling process is much faster.” However, Berkeley Labs is working on a way for heat from the sun to trigger the device.

This announcement comes just three months after Dr. Adrian Koh of the National University of Singapore’s (NUS) Faculty of Engineering announced a similar muscle able to carry 80 times its own weight in September of this year. Both of these devices are at the forefront of more human-like robotics.

Dr. Koh suggests how these micro-muscles will change the game of humanoid robotics. “Our materials mimic those of the human muscle, responding quickly to electrical impulses, instead of slowly for mechanisms driven by hydraulics. Robots move in a jerky manner because of this mechanism. Now, imagine artificial muscles which are pliable, extendable and react in a fraction of a second like those of a human. Robots equipped with such muscles will be able to function in a more human-like manner – and outperform humans in strength.”

Robots like those seen in the big budget Hollywood film “I, Robot” may no longer be an Asimovian dream, finding reality instead through people like Wu and Dr. Koh.