Performance of a Compliant Structure for a Thermal Resonant Microgyroscope

Realizing a structure that allows integration of actuation and sensing components operating at identical frequency is critical from functional standpoint of resonant microgyroscope. This paper presents the design and experimental test results of a compliant nickel structure for a microgyroscope. The device consists of three suspended proof masses supported by in-plane flexures anchored to the substrate thereby enabling to realize distinct driving and sensing components. Chevron-shaped beams driven electrothermally were employed for actuating drive component while parallel electrostatic combs were employed for sensing the Coriolis force induced rotation. Experimental investigation of the dynamic performance of the actuator and sensor structures revealed that their operating frequencies are very close (within 1%) thereby enabling to realize resonant microgyroscope with increased sensitivity. Comparison of the experimental results with the predictions made by analytical and finite-element models agreed well within 15%. Design guidelines for realizing microgyroscope with improved performance were briefly discussed highlighting the challenges associated with the frequency tuning.