14 DAY TRIAL // A team of experts at the US Department of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) announces the development of a micro-sized robotic torsional muscle/motor, which is made entirely out of an amazing material called vanadium dioxide (VO2).
Even before this research, VO2 was prized for its tremendous capabilities, including the ability to change its physical identity, size, and shape depending on its environments. With the new achievement, the material is ready to enter the hall of fame, alongside compounds such as graphene.
The new torsional muscle/motor is around 1,000 times stronger than a sample of human muscle of the size, and can easily throw items up to 50 times its size over a distance equal to five times its lengths. The material requires just 60 milliseconds to do this, which is faster than we can blink. s
The new experiments were led by research physicist Junqiao Wu, who holds joint appointments with the Materials Sciences Division at Berkeley Lab, and the Department of Materials Science and Engineering at the University of California in Berkeley (UCB).
The expert was also the corresponding author of a new paper detailing the study, which was published in the latest issue of the esteemed scientific journal Advanced Materials. Other study coauthors include scientists Kai Liu, Chun Cheng, Joonki Suh, Sangwook Lee, Jian Zhou, and Leon Chua.
“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,” Wu says of the research.
“Using a simple design and inorganic materials, we achieve superior performance in power density and speed over the motors and actuators now used in integrated micro-systems,” the expert goes on to say.
VO2 is very popular among researchers because it is a part of a very select class of materials that are insulators at low temperatures, but become conductive to electricity at temperatures over 67 degrees Celsius, or 152 degrees Fahrenheit.
This shift in electrical conductivity is accompanied by a structural phase transition, which is itself caused by temperature as well. This transition means that one edge of the material expands, while the other two contract, when sufficiently high temperatures are applied.
“Miniaturizing rotary motors is important for integrated micro-systems and has been intensively pursued over the past decades. The power density of our micro-muscle in combination with its multi-functionality distinguishes it from all current macro- or micro-torsional actuators/motors,” Wu concludes.