| Summary: | The health effects of suspended particulate matter (PM) in the air are well documented; however, there is a lack of convenient tools to recognize and quantify PM onsite. Here, we design and fabricate a portable PM analysis system to realize onsite aerosol particle analysis. The system contains a micromachined virtual impactor (VI), a thermophoretic deposition chip, and a smartphone-based portable imaging device. The silicon dioxide (SiO<sub>2</sub>) particles and polystyrene sphere (PLS) particles are used to verify the micro-sized VI with an accurate cut-off diameter of <inline-formula> <tex-math notation="LaTeX">$2~\mu \text{m}$ </tex-math></inline-formula> (PM2). After separation, the fine particles are thermally deposited on a replaceable film. Then, a smartphone connected with a hand-held optical microscope is applied to directly image and analyze the deposited particles with the assistance of a self-developed Android application; thus, the size and distribution of the particles can be acquired immediately. The PM analysis device is successfully applied to analyze the particle content from a smoking cigarette as a real complex sample demonstration. Considering the compact integration of the particle separation, collection, detection, and analysis components, the reported PM analysis device is promising for point-of-need outdoor and indoor air quality monitoring.
|
|---|