MEMS-Enabled Miniaturized Particulate Matter Monitor Employing 1.6 GHz Aluminum Nitride Thin-Film Bulk Acoustic Wave Resonator (FBAR) and Thermophoretic Precipitator

摘要

We describe a miniaturized MEMS particulate matter (PM) monitor that employs the deposition of particulates from a sample stream onto a 1.6 GHz piezoelectric thin-film bulk acoustic wave resonator (FBAR) by means of thermophoresis, and determination of the mass deposited by measuring the resonant frequency shift of a Pierce oscillator. Real-time measurements made in an environmental chamber over several weeks and during a week-long field study in a residence showed excellent correlation with the responses of other commercial aerosol instruments. An added mass of 1 pg could be resolved with the sensor, and the level of detection was 18 μg/m{sup}3. The monitor weighs 114 g, has a volume of approximately 245 cm{sup}3, consumes less than 100 mW, and would cost less than USD100 USD in small quantities. Efforts to further miniaturize the sensor and integrate it with a cell-phone are described.