Integrated multilayer high aspect ratio milliactuators

Abstract

We report here an integrated multilayer high aspect ratio process, and mm-sized electromechanical actuator structures fabricated by this process. The high aspect ratio microfabrication process allows the generation of structures an order of magnitude larger than conventional structures in all three dimensions, while still retaining the minimum in-plane features. We will describe a detailed example of a 1-mm-sized microfabricated actuator with a linearized output capability of 0.2 mN when driven at 60 V. In addition to the high aspect ratio microfabrication process, the high force output is achieved through an area-efficient design and a large-signal linearization scheme. The area-efficient design allows full utilization of the chip area for energy conversion. The large-signal linearization scheme permits a linearized force output with driving voltages as large as the biasing voltage. This increased output force enables the batch-fabricated microactuators to be used in many new, practical applications in which the microactuators are required to move an additional load as well as their own mass. Other structures made possible by this process are fully-integrated wobble micromotors with notched pin-joints for extended high aspect ratio gaps between rotors, stators and axles. © 1995.