The actuation performance of dielectric elastomers (DE) is determined by the electric field when voltages are applied. As the field-dependence is quadratic, higher voltage leads to more efficient actuation. The limiting factor, however, is dielectric breakdown. Due to early-stage and complex manufacturing processes, thin films at present may still contain local imperfections, limiting the overall breakdown field and sometimes causing early breakdown in DE actuators. In particular, when manufacturing multi-layer actuators, a premature breakdown in only one layer causes failure of the entire actuator system. To overcome this problem and to increase the yield of functional actuators, this paper presents a novel method to test and repair DE layers. In a first step, a DE layer is tested for required breakdown voltage in a specially designed breakdown tester and the location of early breakdown spots is identified. In a second step, a method for the repair of these breakdown spots is introduced. A final validation of the repaired DE layer for quality control concludes the process, hence ensuring higher yield of functional actuators in an early manufacturing stage. The testing process using a specially designed breakdown box is described as well as the subsequent repair method of a patch/glue combination. Results about the influence of the repaired spots on the stress/strain behavior of a silicone thin film w/o electrode as well as the performance of the DE prepared with screen-printed carbon black electrodes are included in the presentation.
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