Carbon nanotube muscle 100 times stronger than normal muscle has been created. Spinning carbon nanotubes into yarn a fraction of the width of a human hair, researchers have developed artificial muscles that exert 100 times the force, per area, of natural muscle. This is according to Ray Baughman, director of the Nanotech Institute at the University of Texas at Dallas, who presented the research in Boston last week at the Materials Research Society conference.
Artificial muscles–actuators based on such materials as certain types of metals and polymers that shrink, grow, or change shape–are useful for prosthetic limbs, microscale machines, and robots.
Several issues still must be corrected. As greater loads are applied to actuators, they can start to exhibit “creep”–that is, they do not completely return to their original state with successive cycles. Baughman says that before these actuators can be useful, creep must be eliminated. “Under load, the cycle is not reversible–you’ve got a little creep. In most actuator applications, you don’t want any creep.”
Another key issue is scaling up from thin individual threads. Although the carbon-nanotube muscles can outperform natural muscles on a per-area basis, exerting 100 times the force, natural muscles are much larger, making them stronger.