Spiral μ-preconcentrator for gas sensor detection in the ppb range

In the present work, a silicon-based gas chromatographic microsystem is proposed and developed; it consists of a spiral-shaped μ preconcentrator followed by a μ-hotplate sensor matrix. The shape of the preconcentrator was chosen according to technological and gas flow limitations as it is required that the whole gas flow passes trough the absorbent in order to obtain a good concentration factor. Therefore, a spiral-shape configuration was adopted with 10cm length, and width/depth of 300μm. In this case, the carrier flow is high enough to avoid stagnation whereas provide a fast evacuation of the gas after applying the desorption thermal pulse. The proposed spiral μ-preconcentrator leads to a robust and highly integrated device able to be incorporated in a GC/MS-gas sensor system.