Modeling of static reliability assessment in dielectric elastomer transducers subject to electric loads

In recent years, Dielectric Elastomer Transducers (DETs) have been of top-notch interest as an alternative solution to conventional mechatronic transduction systems, thanks to their features as low-cost and affordable materials, silence operation, low-power consumption, and high level of energy density. Generally, in their most uncomplicated layout, these devices form an electrostatic system, composed of a Dielectric Elastomer (DE) membrane, embedded between two opposite compliant electrodes, constituting a highly deformable capacitor capable of transforming electrical energy into mechanical and vice versa. However, DETs applicability is strongly affected by several engineering constraints. One of their principal failure modes is related to the electrical breakdown of the DE membrane, which occurs when an applied input electrical load exceeds the dielectric strength of the DE. In order to address this problem, the materials and the input load conditions must be chosen appropriately to assure a desired lifetime of operation. For this purpose, this work proposes a preliminary static reliability assessment procedure to evaluate the failure probability of a DET for static events as the electrical breakdown, with specific electric input load conditions. The resulting reliability model comprises the stochastic comparison of the dielectric strength of the DE material with the extreme values distribution of electrical loads in a specific period, aiming to forecast the reliability evaluation for a more extended period, multiple of the original one.