Effect of screen printing parameters on sensor and actuator performance of dielectric elastomer (DE) membranes

Screen printing represents an effective way for applying stretchable electrodes on silicone thin films for the fabrication of dielectric elastomer transducers (DET). Screen printing allows to manufacture a multitude of patternable designs for actuator and sensor applications, in such a way the same methodology can be used for prototyping as well as for large-scale production. The fabrication of DETs does not only require the development of a flexible, highly conductive electrode material, which adheres to a stretched and un-stretched silicone film, but also calls for a thorough understanding of the effects of the different printing parameters. This work studies the influence of screen dimensions (open area, mesh thickness) as well as the influence of multiple-layer-printing on the electrode stiffness, electrical resistance and capacitance as well as actuator performance. The investigation is conducted in a custom-built testing device, which enables electro-mechanical characterization of the DET, performing simultaneous measurements of parameters such as strain, voltage, force, sheet resistance, capacitance, and membrane thickness. Magnified pictures of the electrodes additionally illustrate the effects of the different printing parameters.