A Novel Electromechanical Actuation Mechanism of a Carbon Nanotube Fiber

A spun carbon nanotube fiber functions as a torsional actuator in almost all available environmental media such as air, water, organic solvents, and electrolyte solutions. The Ampere's Law among helically aligned carbon nanotubes explains the simultaneous occurrence of lengthwise contraction and rotary torsion upon applying a low current. The produced stress is over 100 times that of the strongest natural skeletal muscle with high reversibility and good stability. The use of torsional fibers for electric motors is demonstrated.