The new muscles—carbon nanotube fibers spun into a yarn—can produce as much torque, or twisting force, as commercial electric motors.
“This is remarkable,” says James Tour, a professor of chemistry and computer science at Rice University, who was not involved with the work. “To have such torsion in a fiber is fascinating and likely to lead to applications in mechanics that have hitherto been unattainable with any other material. [They] really knocked the ball out of the park on this one.”
The twisty nanotube yarn could open up novel uses. It might help miniaturize electric motors, compressors, and turbines. Tiny pumps based on the rotating actuator could be integrated into lab-on-a-chip devices, which currently use large external pumps. “This is a fascinating new way to provide torsion,” says Ray Baughman, director of the Nanotech Institute at the University of Texas at Dallas. Baughman led the work.
In a paper published on the website of the journal Science today, the researchers show that the new yarn can spin an paddle 1,800 times heavier than itself at 590 revolutions per minute. They demonstrate how a simple device based on this concept could be used to mix two liquids on a microfluidics chip; in a fluid mixer, a 15-micrometer-wide yarn rotated a paddle that was 200 times wider and 80 times heavier than itself at up to one rotation per second.