AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Experimental Evaluation of a Wearable, Bluetooth Enabled, Direct- Reading MEMS PM2.5 Mass Sensor
DORSA FAHIMI, Omid Mahdavipour, John Sabino, Lisa Soderlind, Nobuhiko Fukushima, Hide Nagai, Richard White, Igor Paprotny, University of Illinois at Chicago
Abstract Number: 523 Working Group: Instrumentation and Methods
Abstract This work describes the development and experimental evaluation of a Bluetooth-enabled wearable direct reading MEMS PM2.5 sensor called PM badge. In this sensor, an air-microfluidics circuit separates fine particulate matter from the airstream by means of a microfabricated particle fractionator, and a film bulk acoustic resonator (FBAR) directly measures the mass of the particles deposited on its surface by thermophoresis. PM badge is designed to have a small footprint, reduced power usage, down conversion electronics, and a wireless link to an off-board cellular platform. All the components of the system including resonator electronics, thermophoretic heaters, and fan are run by a single Li-ion battery and all the components are implemented in a small footprint wearable package. A new vertical impactor is developed. The vertical virtual impactor (VVI) is fabricated using a silicon on insulator (SOI) microfabrication process, allowing for its economic integration with the rest of the air-microfluidic circuit. In contrast to the in-plane PM fractionator used in earlier PM sensor prototypes, this fractionator is fabricated such that it can be placed in close proximity to the thermophoretic precipitator/mass sensing element of the sensor. PM badge sensor has been experimentally evaluated in presence of test aerosols and has exhibited the highest sensitivity of 7.56 Hz × m3 / μg × min ever achieved with a direct-read MEMS PM mass sensor. A demo of the new wearable units will be presented at the meeting.