Separation microcolumn assembly for a microgas chromatograph and the like

• US 6,838,640 B2
• Filed: 05/13/2003
• Issued: 01/04/2005
• 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: Potkay, Joseph A., Agah, Masoud, Beach, Katharine T., Sacks, Richard, Wise, Kensall D.
• Primary Examiner(s): Cygan, Michael
• Application Number:
  US10/437,101
• Publication Number:
  US 20030233862A1
• Time in Patent Office: 602 Days
• Field of Search: 392/479, 392/480, 392/481, 392/482, 392/485, 219/209, 219/201, 219/476, 73/233.9
• US Class Current: 219/209
• 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. An assembly comprising:

a sealed structure having a vacuum cavity;

a vacuum sealed microcolumn suspended from the structure in the vacuum cavity wherein heat losses from the device are minimized and the device is thermally isolated; 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.

2. The assembly as claimed in claim 1, wherein the zones are located on a single level.

3. The assembly as claimed in claim 1, wherein the zones are stacked in multiple levels.

4. The assembly as claimed in claim 1, wherein the first microstructure is a rib.

5. The assembly as claimed in claim 4, wherein the rib is a semiconductor rib.

6. The assembly as claimed in claim 1, further comprising a plurality of spaced, individually-controllable heaters distributed along a length of at least one of the zones.

7. The assembly as claimed in claim 1, wherein the structure includes a rim structure.

8. The assembly as claimed in claim 7, wherein the microstructure creates a short thermal circuit to the rim structure.

9. The assembly as claimed in claim 1, wherein the microcolumn is suspended in the vacuum cavity at entry and exit portions of the microcolumn.

10. An assembly comprising:

a sealed structure having a vacuum cavity;

a elongated device suspended from the structure in the vacuum cavity wherein heat losses from the device are minimized and the device is thermally isolated;

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

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.

11. The assembly as claimed in claim 10, wherein the microactuator is an electrostatic microactuator.

12. The assembly as claimed in claim 11, wherein the second microstructure is a plate.

13. The assembly as claimed in claim 10, 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.

14. The assembly as claimed in claim 13, wherein the heater is a plate.

15. An assembly comprising:

a sealed structure having a vacuum cavity;

a elongated device suspended from the structure in the vacuum cavity wherein heat losses from the device are minimized and the device is thermally isolated;

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

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.

16. The assembly as claimed in claim 15, wherein the heater is a plate.

17. An assembly comprising:

a sealed structure having a vacuum cavity;

a elongated device suspended from the structure in the vacuum cavity wherein heat losses from the device are minimized and the device is thermally isolated; 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 wherein the structure includes a rim structure.

18. The assembly as claimed in claim 17, wherein the first microstructure creates a short terminal circuit to the rim structure.

19. An assembly comprising:

a sealed structure having a vacuum cavity;

a elongated device suspended from the structure in the vacuum cavity wherein heat losses from the device are minimized and the device is thermally isolated; 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 wherein the device is suspended in the vacuum cavity at entry and exit portions of the device.