Wireless Love-wave chemical sensor on 41° YX LiNbO3

The design and performance of a novel wireless Love-wave CO₂ sensor using a poly(methylmethacrylate) guiding layer on 41deg YX LiNbO₃ piezoelectric substrate are described. Teflon AF2400 sensitive film provides large CO₂ solubility, permeability and selectivity. A theoretical model is performed to describe wave propagation in Love-wave devices with large piezoelectricity substrate and to allow designing an optimised structure. A coupling of modes model is used to determine optimal design parameters. The gas response properties of the fabricated sensor as the linearity and sensitivity are studied and also a comparison to surface acoustic wave results, are discussed.