An arm-like electrothermal actuator based on superaligned carbon nanotube/polymer composites

A superaligned carbon nanotube film embedded in polymers shows promising applications in the fields of electrothermal actuation because of their homogenous conductivity, good biocompatibility and mechanical properties. We fabricated a simple U-shaped gadget from the composite to investigate the electrothermal actuation mechanism. The gadget can curl to 730 degrees, which is several times larger than existing actuators. A helix. shaped arm. like actuator (artificial arm) was also made from the composite, which exhibited a large twisting deformation (more than 700 degrees twisting, 49.2% length constriction and 26.4% diameter constriction) when driven with low electrical fields (less than 500 V/m or 41 V). The actuation of the U-shaped gadget and the artificial arm can be precisely controlled by the applied voltage or electrical power. The gripping force of the clenched arm is about 4g, 26 times its own weight. This points to a new way for manipulating objects and its potential application in the biomimetic field.