Low Concentration CO Gas Sensor Based on Pulsed-Heating and Wafer-Level Fabricated MEMS Hotplate

In recent years, there has been extensive attention focused on enhancing the response of metal oxide semiconductor-based gas sensors. Herein, we propose a simple pulsed-heating approach to decouple physisorption and surface ionosorption of analyte molecules. The gas sensors exhibit excellent electrical response to carbon monoxide (CO) detection (34.3 for 200 ppm), comparable or better than most advanced CO gas sensors. In contrast to the isothermal mode, pulsed-heating allows for sequential control of various gas sensing processes with distinct temperature dependencies offering a new route to improve sensing responses and lower the limit of detection for health and environmental monitoring.