Giant continuously-tunable actuation of a dielectric elastomer ring actuator

Electric stimulus triggers mechanical deformation in an electroactive polymer actuator, much like the human muscle. Here, we demonstrate a dielectric elastomer actuator in a ring configuration, exhibiting electrically-induced linear strains in excess of 200%. We use theory to inspire the possibility of giant voltage-induced actuation, and create an experimental prototype of a ring dielectric elastomer actuator with continuously-tunable actuation of up to 200% strain. We further demonstrate giant actuation of a free-standing module of ring actuator, pre-tensioned using buckled carbon fibre strips, exhibiting electrically-induced mechanical linear strains in excess of 100% that is continuously-tunable with voltage. Unlike areal strains, displacements from electrically-induced linear strains may be fully utilized to do work, thereby allowing ring actuators to be integrated as actuator modules in robotic systems.