Design and Fabrication of a Meso-Scale Gyroscope

The purpose of this work was to develop a low-cost gyroscope for general aviation. The work was supported by FAA to fulfill their goal of replacing all or part of ground based navigation for general aviation which could help to overcome the difficulties related to GPS failures. To achieve this goal researchers are focusing on MEMS technology. We propose a new design for the gyroscope which should increase the accuracy by increasing the mass of the gyro, that is, produce a meso-scale gyro using MEMS technology and increase signal amplitude by using piezoelectric actuators and sensors (instead of conventional electrostatics). Nb-doped Pb(Zr_20,Ti₈₀)O₃ films were grown on both sides of a 4 inch Pt/TiO₂/SiO₂/Si/SiO₂/TiO₂/Pt wafer by chemical solution deposition. The effective transverse piezoelectric coefficients (-e_3t,f) of these films were measured for the pulse and DC poled films and found to be in the range of 3.21 ~6.36 C/m². These films were then used to fabricate a meso-scale gyroscope using standard photo lithography, wet etching, ion milling and deep reactive ion etching techniques. One side of the film was used for actuation and the other side for sensing of the gyroscope. The resonance frequency of the gyroscope was obtained at 12.60 kHz which matches very well with the simulated results.