The effect of prestretch on the performance of a dielectric elastomer membrane

As one promising material in the family of soft materials, dielectric elastomer can potentially function as transducers in cameras, robots, valves, pumps, energy harvesters and so on due to its capability of large deformation, fast response etc.. The dielectric elastomer transducers are based on the deformation of a soft polymer membrane contracting in thickness and expanding in area, which is induced by the application of a voltage across the two compliant electrodes coated on both sides of the membrane. This paper formulates the out-of plane deformation of a dielectric membrane serving as the key part in a specific actuator designed by Artificial Muscle Inc.. For the actuator, three parameters of design are proposed and called as prestretch. Our attention is focused on exploring the effect of the prestretch on the performance of the actuator. Numerical results show that the true electric field in the membrane tends to be homogeneous under certain prestretch. This indicates that the performance of the actuator can be improved by optimizing the perstretch.