A Micro-Electro-Mechanical System-based bulk acoustic wave piezoelectric disk resonator for detecting z-axis rotation rate

This paper presents a bulk acoustic wave piezoelectric disk resonator based on a special pair of degenerative modes, to detect z-axis angular velocity. A single piezoelectric disk is operated in its appropriate modes in the kHz frequency range to achieve this function. This design combines the bulk acoustic wave drive/sense mode with lead zirconate titanate resonator which improves device’s performance and simplifies its structural complexity. The operation principle of piezoelectric disk resonator is given and validated by finite element method, and the scale factor of piezoelectric disk resonator is 0.977 μV/[(º) · s−1] without any amplification section. The results of impedance analysis for the prototype in the air, which is fabricated on lead zirconate titanate wafer by Micro-Electro-Mechanical System process, show that the resonant frequency of the piezoelectric disk resonator is about 190 kHz. Moreover, the measured frequency split between drive and sense mode is about 290 Hz without any tuning methods. At last, a closed-loop driving and detecting circuit system is designed and its modulation/demodulation method is studied, preliminary experiments show that this device is not sensitive to acceleration, but is sensitive to angular velocity, its performance parameters need follow-up experiments. © 2015, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.