Buckling actuator and sensor based on dielectric elastomers

The actuation technology based on dielectric elastomers represents today the best performing means of electro-mechanical transduction with polymer materials. Dielectric elastomer actuators combine relatively high energy outputs and efficiencies with a high mechanical compliance, low weight and low cost. This paper presents the structure and extended characterization data of so-called buckling actuators, manufactured with a silicone elastomer. These devices show electrically-induced out-of-plane unidirectional displacements of a membrane made of the elastomeric material. The membrane is coupled to an underlying hemispheric support, which provides a passive mechanical bias. The actuators can be equipped with integrated displacement sensors, working according to either piezoresistive or piezocapacitive effects. Performances of fabricated prototypes suggest the suitability of these devices for applications requiring large displacements at low forces.