Effect of geometrical design of support on frequency shift and energy loss of piezoelectric ring resonator applicable to liquid circumstance

A ring-shaped piezoelectric resonator was proposed for health monitoring. The proposed resonator is believed to be experienced several energy loss mechanisms, when used in air or liquid circumstance. Actually, the quality factor of film bulk acoustic resonator in liquid might be decreased to 5% of that in air. So, it is necessary to accomplish suitable structural design and select proper vibration mode to reduce the energy loss of the resonator especially in liquid application. For the pursuit of high sensitivity, we studied the effect of support geometry on frequency shift and energy loss. It was found that low-amplitude vibration area is smaller at narrow support, and frequency shift of trapezoid support is higher than that of rectangle support.