The design, simulation and fabrication of microengineered silicon gyroscopes

Abstract

This thesis is concerned with the development of a low cost resonant gyroscope, or rate of turn sensor, which is capable of being mass produced. The history and theory of the resonant gyroscope is reviewed, and then a survey of resonant gyroscope technology is presented. Two novel designs of resonant gyroscopes are described. These designs are developed using the finite element analysis method. The fabrication procedure required to manufacture these devices is also developed and presented. The fabrication procedures are based upon silicon micromachining technology developed from the semiconductor industry. Prototype structures are fabricated. The first of these devices has been demonstrated to operate successfully as a gyroscopic rate of turn sensor. A third design is also presented and developed using finite element analysis. This design demonstrates for the first time that it is possible to sense rates of turn about all three orthogonal axes independently, using just a single structure. A successful implementation of a structure of this type would eliminate the traditional requirement of one gyroscope per axis of rotation. The finite element simulations of the structure indicate that the design is suitable for mass production using silicon micromachining techniques.