FEM modeling of SAW organic vapor sensors

A finite element method (FEM) simulation approach of surface acoustic wave (SAW) organic vapor sensors was investigated. The effects of the polymer coating on the propagation characteristics of the SAW were studied by FEM modeling in the absence and presence of vapor. The sensitivities for each vapor-coating combination can be obtained from the simulation frequency shift in different vapor concentration. Comparisons of the simulation sensitivities of SAW vapor sensors with the experimental values reported by Edward T. Zellers and co-workers confirm the general validity of the approach. The approach is expected to select polymer, which offers the best sensitivity for particular vapor.