Thickness shear SMR resonator based on Yttrium-doped AlN for high sensitive liquid sensors

AlN doped with transition metals becomes the key for high performance acoustic wave devices due to its improved piezoelectricity after the incorporation of dopants. In this paper, solidly mounted resonator (SMR) based on Yttrium (Y) doped AlN and operates in thickness shear (TS) mode is numerically studied for liquids characterization. The modeling of the TS-SMR is done by finite element analysis and the results are compared to experimental data for validation. After that, the effect of Y concentrations on the acoustic displacement profiles, the resonance frequency and the admittance of the SMR is investigated. The sensitivity of the TS mode resonator to liquids mass loading, viscosity and conductivity is studied for different Y concentrations and different glycerol-in-water contents. The obtained results show that doping AlN with Y enhances the electromechanical and liquids sensing capabilities of TS-SMR and contributes in the development of high sensitive sensors for liquids characterization.