Silicon μ-preconcentrator for improved gas detection

Abstract

In this study we present a μ-preconcentrator unit fabricated with silicon technology. The unit consists of a 3D-microheater surrounded by an insulating membrane. The preconcentrator is made up of a grid of suspended silicon bars underneath a polysilicon resistor. The grid was formed by 40 μm-wide, 520 μm-depth, 3000 μm-long silicon bars fabricated by deep reactive ion etching covering a 3 x 3 mm2 area. This type of silicon grid structure allows holding large amount of absorbent materials and provides efficient heat diffusion.