各種工業上的應用和環境監控之所需，促使氣體感測器技術快速發展。本文將介紹氣體感測器的發展與原理，並呈現本研究團隊以CMOS MEMS技術所製作之濕度感測器與一氧化碳感測器晶片。這兩種感測器皆為電阻式感測器，其構造包含感測器薄膜、感測器電阻、微加熱器和積體電路。利用凝膠溶膠法製備感測薄膜，並將之被覆於感測器電阻上，當感測薄膜吸附感測氣體時，間接使得感測電阻產生改變，晶片中的積體電路則將感測電阻的變化轉換為電壓輸出。實驗結果顯示濕度計的靈敏度為4.5 mV/% RH；一氧化碳感測器靈敏度為1mV/ppm。

Various industrial applications and environmental monitoring require gas sensors so that they develop rapidly. In this paper, the development and principle of gas sensors will be introduced, and the CMOS MEMS humidity sensor and carbon monoxide (CO) sensor developed by my research term will be presented. Both of the gas sensors, which are resistive type, consist of a sensing film, a sensing resistor, a micro heater and readout circuits. The sensing film that is prepared by sol-gel method is coated on the sensing resistor. When the sensing film absorbs or desorbs sensing gas, the sensing resistor changes in resistance. The readout circuits are employed to convert the resistance variation of the sensing resistor into the output voltage. Experiments show that the humidity sensor has a sensitivity of 4.5mV/% RH at 60℃ and the CO sensor has a sensitivity of 1mV/ppm.