A nitric oxide gas sensor based on Rayleigh surface acoustic wave resonator for room temperature operation

摘要

Department of Chemical Engineering, I-Shou University, Kaohsiung, Taiwan; Department of Electrical Engineering, I-Shou University, Kaohsiung, Taiwan; Department of Electrical Engineering, I-Shou University, Kaohsiung, Taiwan;%A Rayleigh surface acoustic wave (RSAW) resonator with polyaniline/tungsten oxide nanocomposite thin film is investigated as a gas sensor for detecting the presence of nitric oxide (NO) in air. The sensor developed in this work was sensitive to NO gas at room temperature. It is shown that the sensor had a frequency shift of 1.2 ppm when it was exposed to 138 ppb NO. The negative frequency response increased with NO concentration increasing. The response and recovery times of the NO sensor in this work were about 20-80 s. In addition, this RSAW sensor also exhibited reversibility and repeatability to the presence of NO gas. Especially, the presented sensor showed high selectivity with NO gas to separate from NO_2 and CO_2 gases.