Multilayer Dielectric Elastomer Actuators with Ion Implanted Electrodes

We present the design, fabrication process and characterization of multilayer miniaturized polydimethylsiloxane (PDMS)-based dielectric elastomer diaphragm actuators. The conductive stretchable electrodes are obtained by low-energy metal ion implantation. To increase force, decrease the required voltage, and avoid dielectric breakdown, we present here a technique to fabricate multilayer devices with embedded electrodes with complex shapes. By implanting electrodes on a partially cured PDMS film, then casting on it the next layer of PDMS, it is possible to have the compliant electrodes "molded" inside PDMS. Using custom shadow masks allows defining electrodes of any shape or size, we report sizes down to 0.1 mm. The minimal distance between independent electrodes inside the PDMS is limited solely by the breakdown voltage of PDMS and can be also as small as 0.1 mm. Using this approach, we have fabricated miniature compact devices consisting of several independent dielectric elastomer actuators on a single PDMS film. Applying different voltages to the separate actuators allows to achieve complicated movements of the whole device, e. g. to act as a 3-DOF parallel manipulator. A distinctive feature of the multi-layer actuators is that they attain similar strain with lower voltage than the single-layer actuators of the same thickness. We report on a 3 mm diameter 2-axis beam steering device combining three actuators.