Challenges in the microfabrication of dielectric elastomer actuators

摘要

Dielectric elastomer actuators (DEAs) have been demonstrated for meso- and macro-scale applications, but only a few devices have been shown at the micro-scale, the most common of which have been diaphragms that bulge out of the plane of the wafer. Microscale DEAs would be of value in a wide range of small devices, including micro-robots, micropumps, and micro-optical systems. An additional advantage of miniaturizing is a reduction in the required driving voltage from kilovolts to tens of volts because the layers are thinner. However, fabrication of micro-scale DEAs remains challenging, due in part to the fact that the vast majority of macro-scale materials and/or fabrication methods cannot be adapted to the micro-scale. On the micro-scale, the elastomers must be deposited as thin films, they must be patternable, and they must be compatible with the other materials used during fabrication, such as sacrificial layers. The realization of compliant electrodes must also be handled in a new way. To fully realize the potential of micro-DEAs, it would also be desirable to develop fabrication procedures for integrating the micro-scale DEAS with complementary metal-oxidesemiconductor (CMOS) driver circuits and other micro-electro-mechanical systems (MEMS). This article addresses the progress that has been made thus far in making microfabricated DEAs, as well as the challenges and the key areas in which additional research needs to be pursued.