A novel NO2 gas sensor using dual track SAW device

A nitrogen dioxide (NO2) gas sensor using dual track surface acoustic wave (SAW) device was developed and fabricated in this paper. The dual track architecture and the MSCs were skillfully applied to the sensor. The external perturbations were eliminated by the dual track architecture, and the bulk acoustic wave (BAW) was suppressed by Multistrip coupler (MSC). The input IDT apodized by Morlet wavelet function can improve the side lobe rejection compared with uniform IDT. Utilizing Tungsten powders, hydrogen peroxide, absolute methanol and polyvinylpyrrolidone as raw materials, the micro-porous network Tungsten trioxide (WO3) film sensitive to NO2 gas was fabricated in measurement acoustic track of dual track SAW device. Experiments results confirm that the NO2 gas sensor using dual track SAW device has good response characteristics to different concentrations NO2 gas from 0.5 ppm to 10 ppm. Furthermore, the NO2 gas sensor using dual track SAW device has good reproducibility and stability.