Quality factor determination and improvement of piezoelectric driving multilayer resonator

Different from a single layer structure, the quality (Q) factor of a multilayer resonator is more difficult to be determined and has not been studied sufficiently. In this paper, we present a simulation method to calculate and improve the Q factor of a piezoelectric driving multilayer resonator (PDMR). The Q factor dependent on damping of the piezoelectric and bonding layers were investigated, and the influence of the parameters, which are independent from material damping loss such as Young's modulus, and the thickness of each layer is discussed. We demonstrate that the bonding layer and the piezoelectric layer affected the Q factor of the multilayer beam dramatically, and the influence of Young's modulus, and that thickness should also be considered. According to the optimization rules, PZT8 and gold-indium were applied to replace the initial PZT5H and conductive resin as the piezoelectric and bonding layers. The experimental results show that the simulation method can well predict the Q factor of the PDMR, and an improvement of the Q factor from 74 to 1064 was obtained.