A Nitrogen Dioxide Surface Acoustic Wave Sensor Based on Polyaniline/Tungsten Oxide Nanocomposite

A surface acoustic wave sensor (SAW) based on polyaniline/tungsten oxide nanocomposite thin film was used to detect nitrogen dioxide at room temperature in this study. Polyaniline/tungsten oxide nanocomposite structure was fabricated from the aniline monomer and tungsten oxide gel. The coupling of modes (COM) theory was used to design the SAW device and simulate the performances of the SAW device. The theoretical simulation of the SAW device was similar to the experimental results. The presented SAW sensor exhibited reversibility and repeatability with reasonable response time when nitrogen dioxide was in ppm level at room temperature. The frequency shift of sensor was 0.5 ppm to 11 ppm nitrogen dioxide.