Fabrication and Application of Miniaturized Dielectric Elastomer Stack Actuators

Abstract

In dielectric elastomer stack actuators (DEAs), the driving voltage is reduced using thin dielectric layers. They are efficiently fabricated in an automated process. To produce thin dielectric films, uncured polydimethylsiloxane (PDMS) is spun to a thickness below 100 μm. After curing graphite, electrodes are sprayed on the PDMS surface and the next dielectric film can be applied on top. The main process steps are explained in detail. We show that the thickness variation within one layer is smaller than 4%. The electrodes are sprayed to have a sheet resistance of 10 kΩ/sq. The technology presented here is able to produce DEAs with layer thicknesses down to 5 μm. Hence, it is possible to design and fabricate actuators, which are driven only at 150 V. Arrays of small actuators with a resolution of 1 mm can be produced as well as single actuator elements with a diameter up to 40 mm. Finally, the potential of this technology is demonstrated by two examples varying highly in their application. The first application is a vibrotactile display. It generates a perceptive vibration of 125 Hz at a driving voltage of 600 V. The second application is a peristaltic pump with a maximum flow rate of 12 μL/min.