A MEMS-based Benzene Gas Sensor with a Self-heating WO3 Sensing Layer

作者：Ke Ming Tsun; Lee Mu Tsun; Lee Chia Yen^*; Fu Lung Ming

来源：Sensors (Switzerland), 2009, 9(4): 2895-2906.

DOI：10.3390/s90402895

• benzene, gas sensor
• MEMS
• micro-heater
• WO3 thin film

In the study, a MEMS-based benzene gas sensor is presented, consisting of a quartz substrate, a thin-film WO3 sensing layer, an integrated Pt micro-heater, and Pt interdigitated electrodes (IDEs). When benzene is present in the atmosphere, oxidation occurs on the heated WO3 sensing layer. This causes a change in the electrical conductivity of the WO3 film, and hence changes the resistance between the IDEs. The benzene concentration is then computed from the change in the measured resistance. A specific orientation of the WO3 layer is obtained by optimizing the sputtering process parameters. It is found that the sensitivity of the gas sensor is optimized at a working temperature of 300 degrees C. At the optimal working temperature, the experimental results show that the sensor has a high degree of sensitivity (1.0 K Omega ppm(-1)), a low detection limit (0.2 ppm) and a rapid response time (35 s).

• 出版日期2009-4