Millisecond-Level Pulse-Heating Sensing System for MEMS-based Gas Sensors

We have proposed a millisecond-level sensing system for MEMS-based SnO
2
gas sensors. Metal oxide semiconductors (MOSs) gas sensor normally works at high temperature, which is heated by a pair of electrodes on the micro-hotplate. In the conventional method, a constant/DC heating voltage is applied to establish a steady temperature, which demands high power consumption and long gas sensing times. MEMS-based MOSs gas sensors, with low power consumption and low thermal inertia, provide the possibility to employ a millisecond pulsed heating voltage. Herein, a 4×4 sensor array testing system has been prepared based on the pulse-heating strategy. By utilizing line scanning and parallel reading, the system realized the quality discrimination of the sensors with a home-made hardware. To address the instability of the sensing system in pulse-heating mode, Rg-50 ppm/Rg was used to describe the performance of the sensors and the reliability of the system was obviously improved.