Carbon nanotube actuators

Electromechanical actuators based on sheets of single-walled carbon nanotub es were shown to generate higher stresses than natural muscle and higher st rains than high-modulus ferroelectrics. Like natural muscles, the macroscop ic actuators are assemblies of billions of individual nanoscale actuators. The actuation mechanism (quantum chemical-based expansion due to electroche mical double-layer charging) does not require ion intercalation, which Limi ts the Life and rate of faradaic conducting polymer actuators. Unlike conve ntional ferroelectric actuators, low operating voltages of a few volts gene rate large actuator strains. Predictions based on measurements suggest that actuators using optimized nanotube sheets may eventually provide substanti ally higher work densities per cycle than any previously known technology.