High-Q 3D Micro-Shell Resonator with High Shock Immunity and Low Frequency Mismatch for MEMS Gyroscopes

In this work we report an improved design and method for fabrication of precision shell integrating (PSI) resonators for gyroscopes. PSI resonators are designed for lower thermomechanical noise and higher shock tolerance. We demonstrate fused silica (FS) micro-shell resonators with tailored sidewall thickness to tune the stiffness and mass of different regions in the resonators. PSI resonators of 10 mm diameter are demonstrated with low frequency split (1.2 Hz), high Q (7.5 million) and long ring-down time (6 minutes). The resonator's sidewall thickness is tailored to achieve large effective mass (>8 mg) and obtain n=2 wine-glass mode frequency at 6-7 kHz for immunity to vibrations. The shells were successfully tested for survivability under 7000g shock. These parameters are critical in achieving near navigation-grade performance ( , Bias Instability <; 1mdeg/hr) for a MEMS gyroscope.