Mems-based semi-packed gas chromatography column with wavy channel configuration

This paper reports the fabrication and performance of a semi-packed column with wavy channel configuration. The 2-m long, 80-μ m wide, and 300-μ m deep column is made by deep reactive-ion etching (DRIE) technology, and contains embedded circular posts of 30 μ m in diameter. The posts and curved groove increase the overall surface area of the column, which leading to higher separation efficiency. In order to achieve an even flow velocity in the channel, the arrangement position, shape, size of embedded posts are explored by the finite element method (FEM) in the semi-packed wavy gas chromatography column. The simulation results show that the gas samples experience less variation in the velocity profile of the semi-packed wavy column than the semi-packed rectangular MEMS column, and possess shorter mass transfer distance than the open one. The micro-fabricated column is used to separate normal alkanes from C5 to C12 to test its performance. The experimental separation results indicate that the theoretical plate number obtained by the proposed semi-packed wavy gas chromatography device is about 4 times higher than that obtained from the open rectangular column under the same injection conditions.