Finite element modeling and numerical investigation of the effects of miniaturization on the performance of dielectric elastomer actuators

Abstract

When dielectric elastomer actuators (DEAs) are used in micro-scale applications, the resulting area-to-thickness ratio is expected to be much smaller in comparison to that of macro-scale systems. In this case, local effects such as fringing field are expected to have a non-negligible impact on the resulting actuator behavior. As a result, numerical predictions obtained via conventional models, which in turn are based on uniform field assumptions, are expected no longer to be accurate. Motivated by the need to develop and optimize micro-scale DEA applications, this paper presents a numerical study on how the electro-mechanical performances of a DEA are affected when reducing the system scale. In-plane and out-of-plane DEA configurations are investigated via dedicated finite element simulations, in which the system relative dimensions are progressively decreased, and the performance are evaluated in terms of both mechanical (i.e., stroke/force) and electrical (i.e., capacitance) response. The finite element predictions are then compared with the results obtained via commonly used lumped-parameter models based on uniform field distributions. The results obtained provide insights into the scale at which the performance of DEAs can no longer be explained with conventionally used lumped-parameter models, and will pave the way for future DEA cooperative micro-actuator applications.