3-D finite element modeling of SAW sensing system for liquids

Like emerging devices, surface acoustic wave (SAW) sensors received considerable interest towards their integration within lab-on-chip and microfluidic structures. Rayleigh wave sensors are highly sensitive in detecting properties of gas in contact with their surface including mass change, viscosity, density, velocity and electrical conductivity. In this paper, primarily, a novel structure of Rayleigh surface acoustic wave (R-SAW) sensors for charactering a liquid is presented and sensitivities of the different liquids deposited in the well are compared. The fundamentals of the sensing system using R-SAW sensor on X-cut, Y-propagation Lithium Niobate substrate are described. The numerical simulation results of the wave propagation indicated the important role of the fluid density whereas the viscosity influence is very low.