Laser Structuring of Thin Metal Films of Compliant Electrodes on Dielectric Elastomers

Abstract

AbstractDielectric elastomer (DE) transducers are polymer‐based devices consisting of an insulating elastomeric membrane with compliant electrodes on both sides, forming a flexible capacitor that can work as an actuator or sensor. In this report, a new direct and maskless method is presented to pattern‐compliant metallic electrodes specially developed for DE applications. Highly conductive and stretchable nickel‐based electrodes are first sputter deposited onto pre‐stretched membranes, resulting in a wrinkled surface after relaxation. An arbitrary electrode design is directly patterned onto the double‐sided coated DE membrane by means of an ultra‐short pulse laser system with a wavelength of 355 nm. In this way, it is possible to achieve simultaneous ablation of both electrodes on the top and the bottom side of the silicone membrane, as well as a selective ablation of only the electrode facing the laser. With a minimal optical resolution of 20 µm, the laser structuring method opens the path toward the manufacturing of miniaturized DE transducers, such as micro‐scale DE arrays with integrated conductive paths, as well as the integration of optical features like diffraction gratings into the DE electrodes.