Analytical modeling, fabrication and characterization of a 3-DOF MEMS gyroscope based on UV-LIGA process

This paper reports a structural configuration of a capacitive gyroscope having 1-DOF drive and anchored 2-DOF sense modes that allows a wide sense bandwidth and high gain without much scaling down the mass on which the sensing comb fingers are attached. The use of the additional anchoring beam in the sense direction also causes the enhancement in the coupling strength of sense mode resonance frequencies. This device has been mathematically modeled considering decoupled frame anchoring effect, designed and then fabricated by using the economical UV-LIGA technology with nickel as a key structural layer of 9-& mu;m thickness with unequally spaced sense comb fingers with 4 & mu;m and 12 & mu;m capacitive gap, respectively. The overall miniature device size is 3 mm x 3 mm. Vibration characterization of the fabricated devices shows sense mode resonances at 4.96 kHz and 5.58 kHz and drive resonance at 5.48 kHz.