Zeolite-coated microcantilever gas sensor

A novel freon gas sensor consisting of a piezoelectric microcantilever coated with zeolite has been developed. Excited by a PZT layer, the microcantilevers are employed to detect the concentration of gas Freon-12 by the action of the specific molecular sifter. Tests of concentrations from 10ppm to 500ppm are carried out in a practical experimental cell. The results show that the relationship between the frequency shift and the concentration is linear for concentrations lower than 100ppm. The minimum mass changing of 3.5/spl times/10/sup -9/ g and the sensitivity of -0.0026%/ppm also can be determined from the experimental results.