Simulation for viscoelastic effects of SH-SAW biosensor

This paper describes a simulation for the shear horizontal surface acoustic wave (SH-SAW) immunoassay biosensor on quartz. A simulation method which was proposed by Campbell and Jones has been generally used to calculate SH-SAW propagation characteristics. In the analysis of the bioreactions with mass loading, the sensitivities of SH-SAW biosensors are too small to confirm the experimental results. In the analysis of the bio-reactions with viscosity sensitivity, the absolute values of velocity and attenuation changes of SH-SAWs agreed with the experiments. In this paper, we analyze the bio-reactions as viscoelastic sensitivity of SH-SAW biosensors using a numerical calculation method. In order to confirm the proposed numerical analysis, 250MHz SH-SAW biosensors on quartz substrates were tested using different thickness of bovine serum albumin (BSA) layers. A simple viscoelastic model is applied to explain the experimental results.