Separation microcolumn assembly for a microgas chromatograph and the like

• US 20030233862A1
• Filed: 05/13/2003
• Published: 12/25/2003
• Est. Priority Date: 05/13/2002
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Wise, Kensall D., Potkay, Joseph A., Agah, Masoud, Beach, Katharine T., Sacks, Richard
• Granted Patent: US 6,838,640 B2
• Time in Patent Office: Days
• US Class Current: 73/23.39
• CPC Class Codes: G01N 2030/025 Gas chromatography
• CPC Class Codes: G01N 2030/3084 ovens
• CPC Class Codes: G01N 2030/8881 Modular construction, specially adapted therefor
• CPC Class Codes: G01N 30/30 of temperature
• CPC Class Codes: G01N 30/60 Construction of the column
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize

Abstract

A high-sensitivity, separation microcolumn assembly for a microgas chromatograph and the like is provided. The assembly has an ultra-low mass complete with integrated heaters. The assembly uses multiple zones for temperature control, and microstructures that permit very rapid heating and cooling of the microcolumn.

Claims

1. A separation microcolumn assembly comprising a plurality of connected sections, each of the sections including:

a substrate having a plurality of closely-spaced, gas-flow microchannels etched therein; and

a cover connected to the substrate to sealingly close the microchannels.

2. The assembly as claimed in claim 1, wherein the substrate is a wafer-based substrate.

3. The assembly as claimed in claim 2, wherein the cover is a glass wafer bonded to the substrate.

4. The assembly as claimed in claim 1, wherein the cover includes a dielectric layer.

5. The assembly as claimed in claim 4, wherein the dielectric layer is a CVD film.

6. The assembly as claimed in claim 1, further comprising a base layer formed on surfaces defining the microchannels to serve as a base for stationary phase deposition.

7. An assembly comprising:

an elongated device; and

a first microstructure having high thermal conductivity for dividing the elongated device into temperature zones and to thermally isolate the zones from each other.

8. The assembly as claimed in claim 7, wherein the zones are located on a single level.

9. The assembly as claimed in claim 7, wherein the zones are stacked in multiple levels.

10. The assembly as claimed in claim 7, wherein the first microstructure is a rib.

11. The assembly as claimed in claim 10, wherein the rib is a semiconductor rib.

12. The assembly as claimed in claim 7, further comprising a plurality of spaced, individually-controllable heaters distributed along a length of at least one of the zones.

13. The assembly as claimed in claim 7, further comprising a second microstructure having high thermal conductivity and a microactuator for moving the second microstructure to a cooling position to cool one of the temperature zones in response to an electrical signal.

14. The assembly as claimed in claim 13, wherein the microactuator is an electrostatic microactuator.

15. The assembly as claimed in claim 14, wherein the second microstructure is a plate.

16. The assembly as claimed in claim 7, further comprising a heater and a microactuator for moving the heater to a heating position to heat one of the temperature zones in response to an electrical signal.

17. The assembly as claimed in claim 16, wherein the heater is a plate.

18. The assembly as claimed in claim 13, further comprising a heater and a microactuator for moving the heater to a heating position to heat one of the temperature zones in response to an electrical signal.

19. The assembly as claimed in claim 18, wherein the heater is a plate.

20. In a microgas chromatograph, a micromachined, separation microcolumn assembly to separate a gas sample flowing therethrough into separate compounds, the assembly including a plurality of connected sections, each of the sections including:

a substrate having a plurality of closely-spaced, gas flow microchannels etched therein; and

a cover connected to the substrate to sealingly close the microchannels.

21. In a microgas chromatograph, a micromachined, separation microcolumn assembly to separate a gas sample flowing therethrough into separate compounds, the assembly comprising:

a microcolumn; and

a first microstructure having high thermal conductivity for dividing the microcolumn into temperature zones and to thermally isolate the zones from each other.