High performance, electrolyte-free torsional and tensile carbon nanotube yarn composite muscles

Abstract

The concept of deploying strong carbon nanotube yarns as actuators has produced both electrochemically and thermally powered yarn muscles. The performance of electrochemically powered yarn muscles is adversely affected for most applications by the need for electrolyte,counter electrode, and device packaging, which add much more to actuator weight and volume than the actuating electrode. The electrolyte also limits operating temperature and voltage, as well as actuation rate. Previous work has demonstrated use of polymer-filled non-twisted carbon nanotube yarns as thermally powered shape memory actuators, but reversible actuation was not achieved. Dispersed carbon nanotubes and nanotube sheets have been used for electrically heating thermally actuating materials to provide cantilever deflections