Investigation and enhancement of the adhesion properties for an optimized lamination of DE multilayer stack transducers
Transducers based on dielectric elastomers (DE) have gained a lot of attention within the last few years. Due to an electric field, the elastic material covered with electrodes on both opposing sides deforms. This effect is applicable for generator and actuator applications. To increase the absolute deformation multilayer, DE transducers are used. In order to transmit tensile forces, the adhesion between each layer has to be sufficiently high. Therefore, the adhesion between the layers and between the layer and the electrode are investigated within this publication. Different adhesion theories are presented and assessed in terms of effectiveness and their influence on electromechanical characteristics. To determine the parameters influencing the adhesion, the theory according to Johnson, Kendall and Roberts (JKR theory) is studied and an approach to increase the adhesion of rough surfaces is deduced. Furthermore, methods to enhance the adhesion are presented and executed. In particular, a surface plasma treatment is conducted and the influence of different electrode composites is investigated with respect to their bonding properties of the multilayer DE composite. To assess the enhancement capability, T peel tests are carried out proving the peel resistance against delamination. Besides that, surface resistance and dielectric breakdown strength are analyzed to investigate the influence of surface treatment on the electric properties. Finally, a conclusion summarizes the obtained results.