Bistable dielectric elastomer actuator with directional motion

Soft actuators based on electroactive polymer (EAP) and shape memory polymer (SMP) have drawn increasing attention, whereas EAP and SMP usually are used as independent functional components. In this work, bistable electroactive polymer (BSEP) with tunable modulus that can be actuated by Maxwell pressure was synthesized. The phase-transition points around ambient temperature were tuned by adjusting the ratio of octadecyl acrylate and soft segment. Bilayer structure was adopted by combining BSEP and passive layer to realize out-of-plane actuation. This actuator can maintain actuating shape without continuously applied stimuli when it is at stable states. Ag nanowires network embedded in BSEP was used as heating electrode, along with carbon nanotube network as high-voltage electrode. Finite element analysis and experiment results show that stiff strips parallelly attached to the actuator can effectively control the actuating direction.