A Low Power Four-Channel Metal Oxide Semiconductor Gas Sensor Array With T-Shaped Structure

A low-power multichannel metal oxide semiconductor (MOS) gas sensor device is presented, including a gas sensor with four gas detecting channels. The device adopts a T-shaped structure having a bridge-type single strip microheater along its horizontal axis, which also houses the four gas detecting channels. The device was designed and fabricated using MEMS technology with SnO
₂
deposited by sputtering as the sensing layer. Based on the temperature gradient of the microheater, at the same heating voltage, the device has a different temperature at each channel. Gas tests for four environmental air pollutants were carried out, and all four channels responded to H
₂
, CO, NO
₂
, and NH
₃
gases with a total power consumption of 21.92 mW. The responses characteristics of two sets of symmetrical channels are different under the same input heating voltage. The response change trend of each channel is also different with different target gas as the input heating voltage changes. [2021-0243]