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/（°） · 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 190kHz. 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.
A new hybrid method, which combines improved glass-blown technology with wet etching, is reported to fabricate micro wine-glass resonators with high-quality fused silica. The optimum placement is ...compared to achieve the resonators with good shell shape. The typical shell diameter is about 4 mm and its thickness covers from dozens to hundreds of micrometers. The etching rates in corrosion solutions with different ratios and at different thicknesses of hemispherical shells are studied. We also conclude how to precisely control the thickness.The corrosion solutions with different ratios of HF solution to NH4 F solution make the spherical shells rougher in different degrees. The best roughness is 0.581 nm in the 1 : 8 ratio corrosion solution while the original roughness is 0.537 nm. This fact shows that the resonator remains atomically smooth surface. Based on the glassblowing spherical fused silica structure, the thickness of the resonator is effectively controlled by buffered oxide etch(BOE)technology according to the measured etching rate. The measured resonant frequency of the hemispherical shell at ambient pressure and room temperature is 1.75 k Hz of rocking mode which is close to the simulated frequency.Using such a low-cost hybrid approach, we can fabricate high-quality microscale resonators in batch.
