A WO3-NPs/MEMS NH3 Gas Sensor

This study exhibits WO3 nanoparticles (NPs) by using ultrasonic wave grinding and fabricates a WO3–NPs/MEMS gas sensor. The experimental results show that the WO3– NPs/MEMS gas sensor responds better to NH3 than to CO, CO2, and SO2. In terms of the stability and the reproducibility of the WO3–NPs/MEMS gas sensor, the average sensing response is about 16% and there is an inaccuracy of <±0.5% when the sensor is operated at 142 °C with 1.3 ppm NH3 gas. The WO3–NPs sensor has a better sensing response to NH3 than the WO3-thin film and original-WO3 powder sensors. This study shows that WO3 nanoparticles have a good sensing response to NH3 gas.