Finite Element Modelling design and optimization of Love Wave mesoporous transducers for biochemical detection in liquid medium

Abstract

We study numerically by a Finite Element Modeling (FEM) approach the design and the optimization of a Love wave transducer coated with a mesoporous sensitive layer. This association could allow to realize an easy functionalizable transducer for biochemical detection in liquid medium. The FEM approach is a good way to design the transducer by estimating many physical parameters in order to obtain a device which could work properly for a given application. Especially, by using a porous layer coated on an acoustic Love wave transducer, we need to be sure that the propagation parameters are still compatible with a usable device. In this paper, after a description of the reduced finite element model of the Love wave transducer, we show that the first experimental results are in a good agreement with the simulations. An “ultra-reduced” FEM approach of the Love wave transducer is carried out for easier consideration of the porous sensitive coating. Finally, experimental transducers are coated with TiO 2 porous sensitive layers by the sol gel technique: the porosity is varied in the range from 10% to 25 %, the pore size from 10 nm to 200 nm, and the thickness from 100 nm to 500 nm. Simulated and experimental results are in good accordance, and allow us to conclude that such transducer could achieve a good propagation of the acoustic wave for biochemical sensing.