Printed Carbon Nanotubes on Polymer Films for Active Origami

We describe a facile fabrication of solid-state actuators by coating common polymer films with a layer of carbon nanotubes. The composite material actuators are multifunctional energy transducers and were powered by heat, light, or electricity. The maximum observed force produced by an actuator was 60 times its own weight. Actuators were also demonstrated to bend more than 90°. The actuators were repeatedly activated for nearly 50,000 cycles without significant loss of performance for a sub-hertz actuator and 1,000,000 cycles in the case of a 30 Hz actuator. The utility of these devices was demonstrated by creating a walking robot.