The influence of viscous and conducting liquids on slot wave in the device based on delay line with shear - Horizontal acoustic wave of zero order

It is known that acoustic waves propagating in thin piezoelectric plates compared with wavelength have high value of electromechanical coupling coefficient. It means that electric fields accompanying such waves deeply penetrate in vacuum. Previously we have shown the possibility of the use of this property for noncontact excitation of acoustic wave in piezoelectric plate placed with some gap above the delay line with propagating piezoactive shear — horizontal acoustic wave of zero order. The excitation of slot wave in such structure leaded to the appearance of the clearly expressed resonant peaks on the frequency dependencies of insertion loss and phase of output signal of delay line. It has been shown that such structure may be used for estimation of acoustic properties of various materials. In this paper the influence of liquids with various values of electrical conductivity, viscosity, and permittivity contacting with upper plate on characteristics of slot wave in such structure was investigated.