Modeling and experimental investigation of multilayer DE transducers considering the influence of the electrode layers

Abstract

A current research topic for dielectric elastomer materials is the reduction of the thickness of the dielectric elastomer layer in order to achieve a lower operating voltage with the same electric field strength. As the ratio of the layer thicknesses of the electrode to the elastomer is therefore more important, the mechanical properties of the electrode layers are of greater significance. Several research articles deal with investigations, exploring the influence of electrode materials on the behavior of the DE transducer and emphasizing its importance. In analytical models, however, the electrodes are not usually considered separately, but the parameters are identified for the entire DE composite, consisting of elastomer and electrode layers. In contrast, in this article the material characterization is carried out separately for the two materials in a first step. In a further step, a holistic model for multilayer DE transducers is derived on the basis of this material-specific characterization and subsequently validated with measurements. For the dielectric elastomer layers, ELASTOSIL ® 2030 (EL 2030), and for the electrode layers, ELASTOSIL ® LR 3162 are investigated, frequently used materials for DE transducers that offer reproducible properties for the investigation. EL 3162 is a carbon black filled elastomer material that exhibits higher elastic and viscose stresses as well as a significant rate-independent hysteresis compared to EL 2030. Experimental investigations of DE transducers with different electrode thicknesses are examined to validate the model and to demonstrate the significance and influence of the electrode layers on the transducer’s performance. Furthermore, the influence of the electrode properties on the actuator, generator and sensor behavior of the DE transducer is analyzed based on the developed model. Depending on the thickness and number of layers, this underlines the relevance of the electrode properties and provides information on the optimized design of the DE transducer.