Microfabricated preconcentrator for quantitative analysis of low concentration volatile organic compounds

A microfabricated preconcentrator that demonstrates vapor trapping ability for part-per-billion volatile organic compounds and integrated temperature sensing for heat transfer measurements is demonstrated. The preconcentrator design accommodates 3.3 mg of carbon adsorbents in a series of three 450 m deep Si cavities fabricated using deep reactive ion etching and sealed using wafer-level Au-Au thermocompression bonding at 400 °C. Backside Pt resistance temperature detectors (RTDs) are integrated to monitor heating rates and study forced convective heat transfer during the thermal desorption cycle where the preconcentrator is heated to 300 °C. The preconcentrator is being developed to enable high-speed chromatographic separations as a part of a low-power, portable microscale gas chromatography system.