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A miniaturized particulate matter (PM) sensing platform was developed. The platform uses a CMOS imager as sensor, electrostatic particle collector to collect ambient PM on an imaging substrate, and a laser diode as light source to scatter light from the particles. Image processing based PM sensing algorithm was developed to obtain particle number, size and size distribution in real time. The system is compact, power efficient, and low cost. The PM sensing platform is suitable for personal PM exposure monitoring with applications in environmental health, occupational and epidemiological studies.

An integrated and miniaturized Micro-Gas Chromatography with real-time imaging capability for simultaneous chemical separation and detection was developed. Surface Plasmon Resonance imaging (SPRi) was used as a sensitive and real-time imaging based detector for various gaseous chemical mixtures and good gas chromatographs were obtained. The system integrated a home-made miniaturized molecular sieve packed spiral micro-channel column with the SPRi imaging chip and real-time chemical separation and detection were demonstrated using alkanes. The chemical separation processes were simulated using COMSOL and matched well with experimental results. The system enabled the study of chemical separation processes in real-time by miniaturizing and integrating the Micro-GC separation and detection units. This approach can be expanded to multidimensional GC development.