Numerical Analysis of Viscosity Effect on Shear Horizontal Surface Acoustic Wave for Biosensor Application

Abstract

A numerical analysis of a shear horizontal surface acoustic wave (SH-SAW) immunoassay biosensor has been investigated. A numerical calculation method proposed by Campbell and Jones has been generally used to calculate SAW propagation characteristics. In this paper, a numerical calculation method for SH-SAW propagation characteristics, which is a modified method of Campbell and Jones involving the effect of liquid viscosity is applied to quartz. In order to confirm the numerical analysis, 250 MHz SH-SAW delay-lines on quartz substrates are tested using glycerol mixtures of different concentrations of 0, 10, 20 and 30 wt%. In the experiments, the velocity and attenuation changes of the SH-SAWs are seen to increase as glycerol mixture concentrations are incrementally increased, as theoretically expected. Very good agreements between theoretical and experimental results are obtained.