Integrated fluidic system for gas chromatography

Patent metadata

Field	Value
Publication number	US-2016103104-A1
Application number	US-201414890771-A
Country	US
Kind code	A1
Filing date	May 16, 2014
Priority date	May 17, 2013
Publication date	Apr 14, 2016
Grant date	—

Abstract

A method is presented for fabricating a fluidic system for a gas chromatograph. The method includes: microfabricating a portion of a fluidic system of a gas chromatograph on a substrate using a first mask; microfabricating a portion of the fluidic system of the gas chromatograph using a second mask; and microfabricating a portion of the fluidic system of the gas chromatograph using a third mask, such that the first mask, the second mask and the third mask are different from each other and the microfabricating of the fluidic system of the gas chromatograph is completed using only the first, second and third masks. A gas chromatograph wherein a microfabricated Knudsen pump is arranged to operate in a first direction to draw carrier gas into a preconcentrator and in a second direction to draw gas out of the preconcentrator.

First claim

What is claimed is:

1 . A method for microfabricating a fluidic system for a gas chromatograph having at least three components, comprising:
microfabricating, using a first mask, a portion of a fluidic system of a gas chromatograph on a substrate; microfabricating, using a second mask, the same or a different portion of the fluidic system of the gas chromatograph; and microfabricating, using a third mask, the same or a different portion of the fluidic system of the gas chromatograph, wherein the first mask, the second mask and the third mask are different from each other and the microfabricating of the fluidic system of the gas chromatograph is completed using only the first, second and third masks.

2 . The method of claim 1 further comprises
microfabricating three components of the gas chromatograph on separate portions of the substrate using only the first, second and third masks;
dicing the substrate into multiple dies, each die having a different sub-assembly for one of the three components disposed on each die; and
stacking the multiple dies to form the gas chromatograph.

3 . The method of claim 1 wherein microfabricating is further defined as one of sandblasting, plasma etching, wet etching and ultrasonic machining.

4 . The method of claim 3 further comprises depositing a metal on the substrate using the first mask, forming a cavity in the substrate using the second mask and forming a through hole in the substrate using the third mask.

5 . The method of claim 4 further comprises microfabricating a pump, a separation column, a preconcentrator, and a detector using only the first, second and third masks.

6 . The method of claim 4 further comprises microfabricating at least one of a pump, separation column, a preconcentrator, and a detector using only the first, second and third masks.

7 . The method of claim 4 further comprises depositing metal on a first substrate and sandblasting on a second substrate.

8 . The method of claim 7 further comprises assembling the first substrate with the second substrate to form at least one of the pump, the separation column, the preconcentrator, and the detector.

9 . The method of claim 8 further comprises assembling the pump, the separation column, the preconcentrator and the detector separately and disposing the assembled components adjacent to each other on a circuit board.

10 . A gas chromatograph, comprising:
a pump configured to receive a carrier gas; a separation column configured to receive the carrier gas from the pump and operable to separate analyte molecules from the carrier gas; a preconcentrator interposed and fluidly coupled between the pump and the separation column; and a detector configured to receive the carrier gas from the separation column, wherein at least three of the pump, the separation column, the preconcentrator and the detector are fabricated by microfabricating using only three different masks.

11 . The gas chromatograph of claim 10 wherein the pump is further defined is a Knudsen pump.

12 . The gas chromatograph of claim 11 having a stacked arrangement, where the preconcentrator is stacked on top of the Knudsen pump, the separation column is stacked on top of the preconcentrator, and the detector is stacked on top of the separation column.

13 . The gas chromatograph of claim 12 wherein the Knudsen pump is comprised of at least one nanoporous membrane sandwiched between glass dies.

14 . The gas chromatograph of claim 13 wherein the Knudsen pump operates in one direction to draw the carrier gas into the preconcentrator and in a second direction to draw gas out of the preconcentrator.

15 . The gas chromatograph of claim 14 further comprises a metal film integrated into dies to serve as heaters.

16 . The gas chromatograph of claim 15 further comprises spacers interposed between the Knudsen pump and the preconcentrator, and spacers interposed between the preconcentrator and the separation column.

17 . The gas chromatograph of claim 10 wherein the preconcentrator includes a chamber which the carrier gas passes through and sorbent granules embedded in the chamber, where the chamber hosts sorbent granules of at least two types.

18 . The gas chromatograph of claim 10 wherein the separation column includes a channel through which the carrier gas passes and the channel has a serpentine pattern.

19 . The gas chromatograph of claim 10 wherein the detector is further defined as one of a pulse discharge detector or a capacitive detector.

20 . The gas chromatograph of claim 19 wherein the capacitive detector includes a channel through which the carrier gas passes and at least one interdigitated capacitor exposed in the channel.

21 . The gas chromatograph of claim 10 having a planar arrangement, wherein the pump is comprised of two or more pumps disposed adjacent to each other on a circuit board to form a pump module, and the preconcentrator, the separation column and the detector are disposed adjacent to one another on the circuit board to form a chromatography module.

22 . The gas chromatograph of claim 21 wherein at least one of the preconcentrator, the separation column and the detector are arranged as a cantilever on a vertical support placed in between the circuit board and the at least one of the preconcentrator, the separation column and the detector.

23 . The gas chromatograph of claim 21 wherein the preconcentrator, the separation column and the detector are fluidly connected together by gas flow connectors, such that the gas flow connectors are fabricated by microfabricating using the same three masks that were used to fabricate the other components of the gas chromatograph.

24 . The gas chromatograph of claim 21 further comprises a reference detector disposed between a port configured to receive the carrier gas from the pump module and the preconcentrator.

25 . A gas chromatograph, comprising:
a pump configured to receive a carrier gas; a separation column configured to receive the carrier gas from a pump and operable to separate analyte molecules from the carrier gas; a preconcentrator interposed and fluidly coupled between the pump and the separation column; and a detector configured to receive the carrier gas from the separation column, wherein the microfabricated pump is arranged to operate in a first direction to draw the carrier gas into the preconcentrator and in a second direction to draw gas out of the preconcentrator, and at least three of the pump, the separation column, the preconcentrator and the detector is fabricated by a microfabricating method.

26 . The gas chromatograph of claim 25 wherein the pump is further defined is a Knudsen pump.

27 . The gas chromatograph of claim 26 having a stacked arrangement, where the preconcentrator is stacked on top of the Knudsen pump, the separation column is stacked on top of the preconcentrator, and the detector is stacked on top of the separation column.

28 . The gas chromatograph of claim 27 wherein the Knudsen pump is comprised of at least one nanoporous membrane sandwiched between glass dies.

29 . The gas chromatograph of claim 28 further comprises a metal film integrated into dies to serve as heaters.

30 . The gas chromatograph of claim 29 further comprises spacers interposed between the Knudsen pump a

Assignees

• Univ Michigan

Inventors

• Gianchandani Yogesh B
• Qin Yutao

Classifications

• G01N2030/8881

  Modular construction, specially adapted therefor · CPC title

• G01N2030/328

  valves, e.g. check valves of pumps · CPC title

• G01N2030/025

  Gas chromatography · CPC title

• G01N30/88

  Integrated analysis systems specially adapted therefor, not covered by a single one of the groups G01N30/04 - G01N30/86 · CPC title

• G01N30/32

  of pressure or speed (G01N30/36 takes precedence) · CPC title