3D silicon electrostatic microactuator

Abstract

The fabrication of a 3D silicon linear microactuator is presented. This actuator is realized by anisotropic chemical etching of a (110) oriented silicon wafer. The silicon monolithic structure of the microactuator is constituted by a fixed part bonded on a glass substrate and a movable part suspended by two elastic beams. The displacement of the movable part is consequently frictionless and is obtained by electrostatic forces. Some mechanical and electrostatic tests are presented. Moreover, with the aim of using this device for microscopy applications, some results have been achieved concerning the isotropic etching of tips on a (110) oriented silicon wafer. It would therefore be possible to integrate a tip onto a movable part for effective application in atomic force or scanning tunneling microscopy.

Microsystem Technology and Microrobotics

“…A frictionless electrostatic microactuator was described in [Tiro93] and [Tiro93a]. A frictionless electrostatic microactuator was described in [Tiro93] and [Tiro93a].…”

A single crystal silicon 3 dimensional processing technique with applications in large displacement electrostatic actuation

“…Several process technologies exist for the fabrication of high-aspect-ratio, single crystal silicon mechanical structures with more than one level (Albrecht et al, 1990;Tirole et al, 1993;Xu et al, 1995;Miller et al, 1997;Tirole et al, 1995). These processes usually involve SOI wafers, wafer bonding techniques or require self aligned levels (Hofmann et al, 1998).…”

“…Methods have been presented before for out of plane (Z directional) actuation (Albrecht et al, 1990;Tirole et al, 1993;Xu et al, 1995;Miller et al, 1997), but large displacements on the order of several microns have always been a problem due to the nature of the process and the actuation mechanism. This process produces high aspect ratio Z directional actuators with displacements of a few microns to several tens of microns.…”

<title>Nonlinear analysis of beams under electrostatic loads</title>

“…Very often microactuators for MEMs are obtained simply by loading beams and plates with electrostatic forces controlled by applied voltages ( [1], [2], [3], [4], [5]). To study the mechanical behavior of the device a linear model generally can not give suitable results; in fact microfabrication techniques allow to design such devices on scales at which electrostatic loads can produce large deflections.…”