Dynamic viscosity change measurement of liquid and liquid crystal using propagation velocity change of shear horizontal wave

Liquid and liquid crystal viscosity are measured in relation to an acoustic phase delay change of a shear horizontal (SH) wave propagating in a cell structure. A phase velocity of the SH wave is related to the liquid or liquid crystal viscosity. Measured results for water solutions of glycerol show linear dependence of the fractional velocity change on the square root of liquid viscosity, which are consistent with the theoretical values. A nematic liquid crystal director reorientation to the applied voltage is evaluated utilizing anisotropy of the viscosity of the liquid crystal molecule. A dynamic viscosity change of the liquid above 0.3 ms can be measured by means of the present technique.