Contractile and buckling actuators based on dielectric elastomers: Devices and applications

Dielectric elastomer (DE) actuators are able to typically show significant electromechanical performances, which make this electroactive polymer technology particularly attractive for so-called 'artificial muscle' devices. This paper deals with two types of DE actuators recently developed in our lab. The first type is represented by the so-called 'folded actuators', based on a simple configuration suitable to easily implement linear contractile devices. The structure consists of a monolithic electroded sheet of elastomer, which is folded up and compacted; the resulting contractile actuator is functionally equivalent to a multilayer stack with interdigitated electrodes, but can be manufactured more easily. The second type of devices is represented by the so-called 'buckling actuators'. They operate with out-of-plane unidirectional displacements of an elastomer membrane. This paper describes the structure and the properties of both these actuators, along with different examples of applications currently being developed in our lab for the biomedical, the robotic and the space fields.