Design and Modeling of Dielectric Elastomer Actuators

One of the main technical challenges in the development of dielectric elastomer (DE) stack actuators is the design and realization of suitable electrodes. They must be compliant and be able to undergo large strains without adding too much stiffness. Metal electrodes are therefore normally out of question due to their high stiffness, though their electrical properties are excellent. In this work a new design approach is presented which comprises rigid metal electrodes. Its functionality is proven by means of numerical simulations and experimental tests. It allows the customized tailoring of transducer elements due to the designable electrode structure. A functional demonstrator is built and tested concerning its electrical, mechanical and electromechanical behavior. For this new actuator type a full electromechanical model is developed. It contains all transfer characterisitcs in a nonlinear description and accounts for various physical effects arising from the special actuator design. Due to its standardized interface configuration it can well be used in combination with existing models for mechanical structures and electrical amplifiers to completely model active systems. It is applicable for the realistic simulation necessary in the development of active solutions with EAP devices. A first longterm test with 10(8) load cycles was performed in order to show the durability of the actuator.