Space charge characteristics of fullerenol and carbon nanotube doped polyurethane elastomer (PUE) actuators

PUE films have been found to exhibit an electrostriction effect. We propose the applying them to a moving device such as an actuator similar to artificial muscles using the electrostriction effect. The actuators are of monomorph type fabricated by PUE film and metal electrodes evaporated at different thickness on the film surfaces. Because these actuators work at a high voltage of more than 1 KV, we controlled the molecular structure of the films by doping C₆₀ or CNT derivatives into PUE so that the actuators could operate under a low voltage. The bends of C₆₀ and CNT-doped actuators were larger than those of non-doped actuators and the working voltage was also low. The force of the actuators increased in proportion to the electric field, and strongly depended on the thickness of the PUE films. Furthermore, in order to clarify the relationship between the stretch of PUE film and the bending mechanism of actuators, we measured the space charge of PUE films using the pulsed electroacoustic method.