Surface Acoustic Wave (SAW) NH_3 Gas Sensor Based on Langmuir-Blodgett Polypyrrole Film

摘要

Surface acoustic wave (SAW) devices have been fabricated and tested as NH_3 gas sensors. Polypyrrole films, prepared by Langmuir-Blodgett (LB) technique, have been deposited onto the surface of SAW devices as gas sorbent layers. Measurements of SAW phase have been carried out in order to investigate the sensing performances of the device. The sensor response shows high sensitivity towards NH_3 gas and excellent selectivity respect to main interfering gases (CO, CH_4, H_2, O_2), at room temperature. The low cross-sensitivity permits the recognition of NH_3 gas as one component of a mixture of interfering gases.