Zeolite-modified microcantilever gas sensor for indoor air quality control

To control indoor air quality, a novel freon gas sensor of piezoelectric microcantilever coated with zeolite has been developed in this paper. Excited by an ac voltage, the microcantilever is employed to detect the concentration of sample freon-12 gas ranged from 0 to 100 ppm by the effect of the specific MFI zeolite modification. High selectivity and sensitivity combined with excellent repeatable and reversible performances are shown. The relationship between the frequency shift in percent and the concentration of freon gas is linear. The minimum mass changing of 3.5×10−9 g and the sensitivity of −0.0024%/ppm are determined from the experimental results.