Miniaturized EAPs with compliant electrodes fabricated by ion implantation

Miniaturizing dielectric electroactive polymer (EAP) actuators will lead to highly-integrated mechanical systems on a chip, combining dozens to thousands of actuators and sensors on a few cm(2). We present here mu m to mm scale electroactive polyer (EAP) devices, batch fabricated on the chip or wafer scale, based on ion-implanted electrodes. Low-energy (2-10 keV) implantation of gold ions into a silicone elastomer leads to compliant streatchable electrodes consisting of a buried 20 nm thick layer of gold nanoparticles in a silicon matrix. These electrodes: 1) conduct at strains up to 175%, 2) are patternable on the mu m scale, 3) have stiffness similar to silicone, 4) have good conductivity, and 5) excellent adhesion since implanted in the silicone. The EAP devices consist of 20 to 30 mu m thick silicone membranes with mu m to mm-scale ion-implanted electrodes on both sides, bonded to a holder. Depending on electode shape and membrane size, several actuation modes are possible. Characterization of 3mm diameter bi-directional buckling mode actuators, mm-scale tunable lens arrays, 2-axis beam steering mirrors, as well as arrays of 72 cell-size (100x200 mu m(2)) actuators to apply mechanical strain to single cells are reported. Speeds of up to several kHz are observed.