文摘
According to the theory of a gas chromatography column, the air flow distribution inside the channel plays a vital role in the peak broadening. Unlike the semi-packed columns which utilized embedded posts to obtain a more uniform lateral distribution compared to the open tubular columns, this paper reports the design and fabrication of a MEMS-based GC column folded in a wavy configuration to achieve an even flow velocity. The wavy column consists of upper arcs and lower arcs which are alternatively connected in series. The flow distributions of wavy columns with various arc angle and curvature radius are explored by the finite element method. The simulation reveals that the average flow velocity decreases with the increase of the arc angle, resulting in a successive improvement of the flow uniformity at the zones between two adjacent bends but also a more nonsymmetric distribution at the bends. These two effects counteract with each other and render an optimal arc angle of 136°. To verify the above design, the 136° wavy column and a serpentine column with the same dimensions are compared, where a better separation performance of the wavy column is demonstrated.