Temperature-compensated Love wave based gas sensor on waveguide structure of SiO₂/36° YX LiTaO₃

Abstract

A temperature-compensated Love wave device was proposed for gas sensing utilizing a waveguide structure of SiO2/36° YX LiTaO3. Significant improvement in the temperature stability of the hybrid Love wave device was implemented by varying the guiding layer thickness. The optimal values yielding low cross-sensitivity to temperature and high mass sensitivity in gas sorption were determined theoretically by solving the coupled electromechanical field equation in layered media. The theoretical analysis was confirmed experimentally in dimethylmethylphosphonate (DMMP) detection by using a fluoroalcoholpolysiloxane (SXFA) coated Love wave sensor. The experimental results indicate that better sensitivity and excellent temperature stability were obtained from the developed Love wave gas sensor over the Rayleigh surface acoustic wave (R-SAW) sensors.