ACTIVELY COOLED VAPOR PRECONCENTRATOR

• US 20100236341A1
• Filed: 03/18/2009
• Published: 09/23/2010
• Est. Priority Date: 03/18/2009
• Status: Active Grant

• Current Assignee: The Government Of The United States As Represented By The Secretary Of The Navy, The United States of America As Represented By The Secretary of Agriculture, University of Louisville
• Original Assignee: The Government Of The United States As Represented By The Secretary Of The Navy
• Inventors: Walsh, Kevin, Aebersold, Julia, Stepnowski, Stanley V., Martin, Michael, McGill, R. Andrew
• Granted Patent: US 8,448,532 B2
• Time in Patent Office: Days
• US Class Current: 73/863.120
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 2001/022 sampling for security purposes, e.g. contraband, warfare agents

Abstract

An analyte collection system device includes an active area that includes a plurality of perforations extending therethrough. The plurality of perforations are arranged to permit passage of an analyte fluid flow through the microscale plate. A heating element is provided for heating the active area, and a thermal distribution layer is disposed over at least a portion of the active area. For cooling the active area at or below an ambient temperature, an active cooler is provided.

Claims

1. An analyte collection device, the device comprising:

a microscale plate having an active area, the active area including a plurality of perforations extending therethrough, the plurality of perforations being arranged to permit passage of an analyte fluid flow through said microscale plate;

a heating element for heating said active area;

a thermal distribution layer disposed over at least a portion of the active area; and

an active cooler for cooling the active area at or below an ambient temperature.

2. The analyte collection device of claim 1, wherein said heating element comprises a resistive trace formed on the active area.

3. The analyte collection device of claim 1, wherein said microscale plate comprises:

a silicon substrate having an upper surface;

a thermal insulating layer disposed on the upper surface;

wherein said heating element is formed on said thermal insulating layer.

4. The analyte collection device of claim 1, wherein said thermal distribution layer comprises a layer of weak thermally conductive material.

5. The analyte collection device of claim 4, wherein said thermally conductive material comprises silicon nitride.

6. The analyte collection device of claim 1, wherein said active cooler comprises a Peltier cooler in thermal communication with said thermal distribution layer.

7. The analyte collection device of claim 1, further comprising:

a layer of sorbent material disposed over said thermal distribution layer.

8. The analyte collection device of claim 6, wherein the Peltier cooler comprises a first electrode/dielectric pair formed on the microscale plate, a P-N layer formed on the first electrode/dielectric layer, and a second electrode/dielectric layer formed on the P-N layer.

9. The analyte collection device of claim 1, wherein said microscale plate comprises:

a first electrode/dielectric layer;

a P-N layer formed on said first electrode/dielectric layer; and

a second electrode/dielectric layer formed on said P-N layer;

said first electrode/dielectric layer and said second electrode/dielectric layer providing a electrical series connection between P and N type conductors.

10. The analyte collection device of claim 1, wherein said active cooler comprises a chilled liquid delivery system in communication with said microscale plate.

11. The analyte collection device of claim 1, wherein said active cooler comprises:

a gas delivery system in communication with said microscale plate;

a device for expanding a gas for delivering via said gas delivery system.

12. The analyte collection device of claim 1, further comprising:

a silicon frame connected to and supporting said microscale plate;

wherein said thermal distribution layer connects said microscale plate and said silicon frame;

wherein said active cooler is positioned to cool said thermal distribution layer.

17. A micro analytical system, the system comprising:

a large volume preconcentrator;

an analyte collection device according to claim 1, said analyte collection device being in fluid communication with said large volume preconcentrator;

a detector system;

a power source; and

a controller.

18. The system of claim 17, further comprising:

a housing for said analyte collection device and said large volume preconcentrator;

an inlet to said housing;

an outlet to said housing; and

means for inducing analyte fluid flow.

19. The system of claim 18, wherein said means for inducing flow comprises a low power fan.

20. The system of claim 18, wherein said large volume preconcentrator and said analyte collection device are separated by a valve.

13. An analyte collection system, comprising:

a plurality of preconcentrator chips, each of said preconcentrator chips comprising;

a microscale plate having an active area, the active area including a plurality of perforations extending therethrough, the plurality of perforations being arranged to permit passage of an analyte fluid flow through said microscale plate;

a heating element for heating said active area; and

a thermal distribution layer disposed over at least a portion of the active area;

an active cooler for cooling each of the active areas below an ambient temperature.

14. The analyte collection system of claim 13, further comprising:

a thermally conductive chip support, said thermally conductive chip support being configured to mount each of said plurality of preconcentrator chips.

15. The analyte collection system of claim 14, wherein said active cooler comprises a Peltier cooler in thermal communication with said thermally conductive chip support, said Peltier cooler comprising a first electrode/dielectric layer and a second electrode/dielectric layer providing a electrical series connection between P and N type conductors.

16. The analyte collection system of claim 15, further comprising:

a heat sink in thermal communication with said second electrode.

21. A method for concentrating analyte from an analyte fluid flow and delivering the analyte, the method comprising:

cooling an active area of a microscale plate to a temperature at or below an ambient temperature, the active area including a plurality of perforations extending therethrough to permit passage of an analyte fluid flow through said microscale plate;

directing analyte fluid flow substantially perpendicular to the active area and through the plurality of perforations to concentrate analyte on a sorbent disposed on the active area;

heating the active surface to desorb the analyte;

delivering the desorbed analyte in a flow substantially parallel to the active area.

22. The method of claim 21, wherein said cooling the active area comprises cooling a thermal distribution layer disposed over at least a portion of the active area.

23. The method of claim 22, wherein said cooling the active area comprises at least one of activating a Peltier cooler, delivering a chilled liquid, vapor-compression cycle cooling, thermionic cooling, vortex tube cooling, air cycle cooling, magnetic cooling, Stirling cycle cooling, Malone refrigeration acoustic cooling, pulse tube cooling, water cycle system cooling, and delivering an adiabatically expanded gas.

24. The method of claim 21, wherein said heating the active area comprises activating an active heater to flash heat the active area.

25. The method of claim 24, wherein said cooling the active area comprises activating a Peltier cooler, and wherein said heating the active area further comprises reversing operation of the Peltier cooler.

26. The method of claim 21, wherein said heating the active area desorbs the analyte in a direction perpendicular to the active area.