Ion-implanted compliant and patternable electrodes for miniaturized dielectric elastomer actuators

This article presents metal ion implantation as an alternative technique to fabricate compliant electrodes for small-size dielectric elastomer actuators. When reducing the size of these actuators to below 1 cm, the ability to pattern the electrodes is added to the need for compliance. Metal ion implantation on Polydimethylsiloxane (PDMS) layers allows the creation of conductive and compliant electrodes, which can be easily defined by photolithography or with a shadow mask. Mechanical testing show that implantation has a limited impact on the PDMS' properties, with a Young's modulus increase of 50%-200% depending on the dose. Uniaxial stretching tests show that conductivity is conserved for strains up to 50% and present no hysteresis. Dielectric breakdown tests were conducted for Au and Pd implantations, which exhibited high breakdown fields (>100 V/um), similar to non-implanted PDMS layers. Other advantages of ion implanted electrodes include transparency and a negligible mass. Buckling mode diaphragm actuators were fabricated with ion-implanted electrodes and exhibited out-of-plane displacements up to 7% of their lateral dimensions.