Continuum vibration analysis of dielectric elastomer membranes

Abstract

Dielectric Elastomer (DE) transducers are well known for the possibility of responding to an applied voltage with relatively large actuation strains, often larger than 100%, and for their relatively high actuation bandwidth (order of several kHz). However, up to date there are relatively few applications which use the dynamic behavior of DEs. Some relevant examples include loudspeakers and fluid dispensers. Motivated by the potentialities of DEs in high-frequency applications, the aim of this work is the investigation of the continuous vibrations observed when DE membranes are actuated electrically. The system under analysis consists of a circular DE membrane pre-loaded with a spring. While exciting the DE membrane actuator with high-voltage, high-frequency signals, the motion of the membrane is detected with a 3D laser vibrometer which uses Doppler effect to reconstruct the system spectrum and vibration modes. An extensive experimental investigation is performed to study the influence of system parameters, such as membrane geometry and pre-stress, on the membrane frequency spectrum and vibrational modes.