Abstract: A wavy micro gas chromatography column includes a silicon substrate and a bonded glass cover. A micro channel having a rectangular cross section is etched on the silicon substrate and coated with a stationary phase film. A projection figure of the micro channel on the silicon substrate includes multiple regular wavy curves. Each wavy curve is formed through alternately connecting first upper arcs with first lower arcs. Because the groove has a curving structure, the carrier gas velocity is decreased as the increase of the arc angle, resulting in an improvement of the flow uniformity at the zones between two adjacent bends but also an enlarging nonsymmetric distribution at the bends. Thus, an optimal curving structure can make the overall flow more even, and in turn achieve a better separation performance compared to the straight channel columns. Meanwhile, a wavy channel realizes a longer column length on a given area.

Abstract: A double-sided diaphragm micro gas-preconcentrator has a micro-gas chamber which is formed by stacking an upper silicon substrate with a lower silicon substrate with a back-on-face configuration. One or more suspended membranes are provided on every silicon substrate. The silicon where the suspended membrane is provided is completely removed for forming a cavity. A thin-film heater is deposited on every suspended membrane. A sorptive film is coated on an inner wall of every suspended membrane. Thus, the upper and lower sides of the preconcentrator in the present invention are suspended membranes, which improve the area of the sorptive film on the diaphragm. As a result, the preconcentrating factor is improved while keeping the small heat capacity, fast heating rate, and low power consumption features of the planar diaphragm preconcentrator.

Abstract: A wavy micro gas chromatography column includes a silicon substrate and a bonded glass cover. A micro channel having a rectangular cross section is etched on the silicon substrate and coated with a stationary phase film. A projection figure of the micro channel on the silicon substrate includes multiple regular wavy curves. Each wavy curve is formed through alternately connecting first upper arcs with first lower arcs. Because the groove has a curving structure, the carrier gas velocity is decreased as the increase of the arc angle, resulting in an improvement of the flow uniformity at the zones between two adjacent bends but also an enlarging nonsymmetric distribution at the bends. Thus, an optimal curving structure can make the overall flow more even, and in turn achieve a better separation performance compared to the straight channel columns. Meanwhile, a wavy channel realizes a longer column length on a given area.

Abstract: A double-sided diaphragm micro gas-preconcentrator has a micro-gas chamber which is formed by stacking an upper silicon substrate with a lower silicon substrate with a back-on-face configuration. One or more suspended membranes are provided on every silicon substrate. The silicon where the suspended membrane is provided is completely removed for forming a cavity. A thin-film heater is deposited on every suspended membrane. A sorptive film is coated on an inner wall of every suspended membrane. Thus, the upper and lower sides of the preconcentrator in the present invention are suspended membranes, which improve the area of the sorptive film on the diaphragm. As a result, the preconcentrating factor is improved while keeping the small heat capacity, fast heating rate, and low power consumption features of the planar diaphragm preconcentrator.