Study of LiTaO3 shear wave resonator for viscosity sensor of polymer liquid in MHz range

We are studying the response of LiTaO₃ shear wave resonator in polymer liquid in MHz range. The element size is small (1.0 × 7.4 × 0.49 mm³). The side faces of the resonator were covered with a highly viscous silicone rubber material. Using Newton fluid theory, the characteristic mechanical impedance of the shear wave in the liquid was derived for the equivalent circuit of the resonator. The analytical values of glycerin were roughly consistent with the experiment using only 0.1cc. the polymer liquid used for the measurement was silicone oil. The static viscosity is from 9.8 to 94,720 mPa·s. The resonance frequency change was from 0.05% to 0.07%. The resonance resistance change was from 57 ohm to 190 ohm. The experimental results were examined using Mason´s equivalent circuit with Maxwell model of a viscoelastic polymer.