A novel MEMS gas sensor with effective combination of high sensitivity and high selectivity

A, novel MEMS gas sensor including a PZT thin film layer and a zeolite layer is developed in this paper, which shows effective combination of high sensitivity and high selectivity. Working in resonating mode, the sensor depicts the mass loading due to molecular adsorption of the zeolite by the frequency shift. The relationship between the frequency shift in percent and the concentration of Freon is linear. The minimum mass loading of 3.5 /spl times/ 10/sup -9/ and the sensitivity of -0.0024%/ppm can be determined from the experimental results.