Finite element analysis of interference for the laterally coupled quartz crystal microbalances

Abstract

Multi-channel quartz crystal microbalance (MQCM) devices have many promising potential applications as sensors to detect the micromass changes in engineering. The frequency interference between adjacent channels is one of the problems for design of the MQCMs. In this paper, a model of MQCM is constructed by finite element analysis (FEA) code ANSYS. The mass sensitivity of the single resonator with different electrode width is examined numerically. The coupling factor is defined to investigate the frequency interference between the adjacent QCMs. The numerical calculation results show that the coupling factor for the detuned QCM pair in one quartz chip is quite weak due to the energy trapping effect of the electrode layer. For a symmetrical QCM pair, the parallel resonance frequency of TSM is reduced almost linearly proportional to the mass absorption on surface, but the anti-parallel resonance frequency is non-linearly reduced. Based on the FEM modeling, the effects of the design parameters of MQCM, i.e. interval spacing between channels, thickness of electrode, and the effect of the layout of QCM pair on AT-cut quartz plate are investigated.