Presently, the torsional actuator has gained a lot of attentions among the area of micro actuators. Because the torsional actuator can not carry a substantial mechanical loading in the out-of-plane direction, it is frequently used in some optical or electrical applications such as light modulators and spatial scanner devices. However, the performance of torsional actuator is limited to the fabrication process and operating conditions. For instance, it is difficult to fabricate a torsional actuator with both large rotating angle and big size moving plate. A novel electrostatically driven torsional actuator is proposed in this paper. The torsional actuator is fabricated through the integration of surface and bulk micromachining processes. Thus the goal of fabricating a torsional actuator with a cavity right beneath the edge of the moving plate is reached. In addition, special design of the driving electrode is also available in this research. The advantage of the proposed design is to increase the traveling distance of the actuator as well as to increase the area of the moving plate. In short, the proposed design provides the possibility of increasing the size of moving plates without reducing its rotating angle. Therefore, the applications of the torsional actuator, such as image scanner and positioner, are widened.

Date Published: 8 September 1998
PDF: 9 pages
Proc. SPIE 3514, Micromachined Devices and Components IV, (8 September 1998);

Published in SPIE Proceedings Vol. 3514:
Micromachined Devices and Components IV
Patrick J. French; Kevin H. Chau, Editor(s)