Modeling of a Diaphragm-Type Viscoelastic Dielectric Elastomer Energy Transducer

In this paper, a diaphragm-type dielectric elastomer energy transducer is theoretically and numerically investigated by considering the viscoelastic behaviors of the material. The transducer is designed in the shape of a circular membrane. The buckling mode of the membrane is therefore harnessed to transform energy between its mechanical form and electrical form. It is shown that viscous dissipation has a significant impact on the electromechanical instability (EMI) of the transducer when it works as an actuator. It is found that, during the actuation, a smaller modulus ratio is easier to incur EMI. It is expected that there is a critical modulus ratio, beyond which a steady state can be achieved by circumventing the stress relaxation-induced EMI. When the transducer works as an energy harvester, viscous effect affects the efficiency of the energy harvester significantly. It is discovered that the efficiency is a function of both the modulus ratio of the material and the pressure ratio from the environment. For a fixed pressure ratio, the efficiency initially drops and then turns upward as the modulus ratio increases from 0 to 1. It is also shown that for the material state with a relatively small modulus ratio, the efficiency decreases as the pressure ratio increases. While for the material state with a relatively large modulus ratio, the efficiency rises along with the pressure ratio.