Design modeling and simulation of electrothermally actuated microgyroscope fabricated using the MetalMUMPs

This paper presents a thermally actuated resonant microgyroscope fabricated using commercially available standard MEMS process MetalMUMPs. Chevron-shaped thermal actuator is being used to drive the proof mass whereas sensing mechanism of the proposed device is based on the parallel plate sensing electrodes. The proposed model consists of three proof masses coupled with each other to be driven in through a frame. To achieve larger bandwidth and increased sensitivity, the proposed model of microgyroscope is operated with a slight mismatch in the resonant frequency. The resonant frequencies of microgyroscope are predicted to be 5.37 kHz for drive mode and 5.02 kHz for sensing mode. Finite element simulations are carried out to predict the performance of the proposed device using the thermo-physical properties of electroplated nickel. A brief theoretical description, dynamics and mechanical design considerations of the proposed gyroscopes model are also discussed. Prototype fabrication using MetalMUMPs has also been investigated in this study. Static simulation predicted a high drive displacement of 4.88 mum at 0.1V_dc whereas dynamic transient simulations predicted a displacement of 0.28 mum when a sinusoidal voltage of 0.1 V is applied. The proposed device has a size of 1.8 times 2.0 mm² with an estimated power consumption of 0.26 Watts.