MEMS Particulate Matter (PM) monitor for cellular deployment

In this work, we present designs, modeling as well as initial results from ongoing fabrication of a novel, portable MEMS Particulate Matter (PM) monitor. The PM monitor uses an air-based microfluidic circuit to select the particles of interest based on their size, and then deposit them onto the surface of a temperature-compensated Film-Bulk Acoustic Resonator (FBAR). The relative change in the resonance frequency of the FBAR provides an indication of the mass of the particles that are deposited on its surface, and correspondingly of the PM concentration in the surrounding air. Our device measures 40 mm × 25 mm × 12 mm, and is 1-2 orders of magnitude smaller than commercially available PM monitors. The use of microfabricated components allowed us to reduce the size of the device by an order of magnitude from our previously developed prototype, while at the same time increasing its sensitivity. Combined with a location-aware cellphone, this technology will allow collection of personal PM exposure data.