μGC Multicapillary Columns with Mono-Layer Protected Gold as a Stationary Phase

This paper reports the first MEMS-based stationary phase coating technique for ultra-narrow single capillary (SCC) and multicapillary (MCC) microfabricated gas chromatography (muGC) columns yielding the highest separation performance reported to date. The conventional coating methods are mainly based on the solvent evaporation of a polymeric solution. These methods, which are developed for fused silica capillary tubing, cannot afford conformal coating in the rectangular-shaped muGC columns with high-aspect-ratio structures. The proposed wafer-level coating technique overcomes this traditional challenge by merging MEMS and nanotechnology. The new muGC stationary phase has been achieved by depositing a uniform functionalized gold layer with an adjustable thickness (150 nm-2 mum) in 25 mum-wide single columns as well as in four-capillary MCCs.