Micro-pillar density modulation in semi-packed MEMS column

For gas chromatography, the separation column is the most important component in influencing performance of a gas chromatography system. The semi-packed MEMS column design has been widely used because it enhances the separation efficiency and provides higher sample capacity. However, a limitation of this type of column is the large pressure drop that occurs across its column length. This paper reports a new semi-packed design that utilizes density modulation of the micro-pillars to improve the pressure drop and increase the separation efficiency for high speed separations.