A layered structure surface acoustic wave for oxygen sensing

A novel layered structure surface acoustic wave (layered SAW) transducer has been employed for an oxygen sensing application. It is a SiO/sub 2/(0.36 /spl mu/m)/ST-cut quartz crystal transducer. The dominant mode propagating in the transducer is a combination of Rayleigh and Love modes. Such a structure has the advantage of confining the acoustic wave energy to the top selective layer, which increases the sensitivity of the device. A TiO/sub 2/ thin film deposited by the sol-gel process has been used as the oxygen sensitive layer.