Design of a linear dielectric elastomer actuator of conical shape with quasi-constant available thrust

A novel design for a Dielectric Elastomer (DE) actuator is presented. The actuator is obtained by coupling a conically shaped DE film with a compliant mechanism. The compliant mechanism is designed to suitably modify the force generated by the elastomer film. The resulting actuator provides a nearly constant force along the entire actuator stroke when the DE film is activated and quickly returns to an initial rest position when the DE film is deactivated. The electromechanical properties of the DE film are measured experimentally. The sizing of the compliant mechanism is obtained through a pseudo-rigid-body model and subsequently verified through finite element analysis. Simulations show that the designed actuator works as desired. Possible applications of this kind of actuator are MRI compatible devices, haptic devices and Braille cells.