Electroosmotic microchannel cooling system

• US 7,185,697 B2
• Filed: 09/02/2004
• Issued: 03/06/2007
• Est. Priority Date: 09/28/2001
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Zeng, Shulin, Santiago, Juan G., Koo, Jae-Mo, Zhang, Lian, Kenny, Thomas W., Huber, David E., Goodson, Kenneth E., Mikkelsen, James C., Jiang, Linan, Laser, Daniel J., Chen, Chuan-Hua, Wang, Evelyn Ning-Yi
• Primary Examiner(s): Walberg; Teresa J.
• Application Number:
  US10/933,068
• Publication Number:
  US 20050098299A1
• Time in Patent Office: 915 Days
• Field of Search: 165/104.33, 165/104.25, 165/104.28, 361/700, 257714-716, 174/15.2, 417/48
• US Class Current: 165/104.33
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: F28D 15/00 Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies F28D17/00, F28D19/00, F28D20/00 take precedence
• CPC Class Codes: F28F 2260/02 having microchannels
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45169 Platinum (Pt) as principal constituent
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2225/06562 at least one device in the stack being rotated or offset
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10158 at the passive surface
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

Apparatus and methods according to the present invention preferably utilize electroosmotic pumps that are capable of generating high pressure and flow without moving mechanical parts and the associated generation of unacceptable electrical and acoustic noise, as well as the associated reduction in reliability. These electroosmotic pumps are preferably fabricated with materials and structures that improve performance, efficiency, and reduce weight and manufacturing cost relative to presently available micropumps. These electroosmotic pumps also preferably allow for recapture of evolved gases and deposited materials, which may provide for long-term closed-loop operation. Apparatus and methods according to the present invention also allow active regulation of the temperature of the device through electrical control of the flow through the pump and can utilize multiple cooling loops to allow independent regulation of the special and temporal characteristics of the device temperature profiles. Novel microchannel structures are also described.

Claims

1. An electroosmotic pump that pumps a fluid having a liquid phase upon application of a voltage comprising:

a fluid chamber having a fluid inlet and a fluid outlet;

an anode disposed within an anode chamber portion;

a cathode disposed within a cathode chamber portion;

a porous structure that provides electroosmotic pumping upon application of the voltage between the anode and the cathode, the porous structure creating a partition in the fluid chamber between the anode chamber portion and the cathode chamber portion;

a catalytic recombiner integrated with the fluid chamber; and

a gas permeable membrane that covers the catalytic recombiner.

2. The apparatus according to claim 1 wherein the catalytic recombiner recombines oxygen and hydrogen.

3. The apparatus according to claim 2 wherein the electroosmotic pump is configured in a closed loop cooling system and the catalytic recombiner provides for the recombination of the oxygen and hydrogen.

4. The apparatus according to claim 3, further including:

a channel disposed between the cathode chamber portion and the anode chamber portion; and

a gas permeable membrane disposed in proximity to the channel that minimizes a passage of the fluid therethrough and allows the passage of hydrogen therethrough.

5. The apparatus according to claim 4 further including a heating element disposed in proximity to the catalytic recombiner.

6. An electroosmotic pump that pumps a fluid having a liquid phase upon application of a voltage comprising:

a fluid chamber having a fluid inlet and a fluid outlet;

an anode disposed within an anode chamber portion;

a cathode disposed within a cathode chamber portion;

a porous structure that provides electroosmotic pumping upon application of the voltage between the anode and the cathode, the porous structure creating a partition in the fluid chamber between the anode chamber portion and the cathode chamber portion;

a catalytic recombiner integrated with the fluid chamber; and

heating element disposed in proximity to the catalytic recombiner.

7. The apparatus according to claim 6 further including a gas permeable membrane that covers the catalytic recombiner to keep it dry.

8. The apparatus according to claim 6, further including:

a channel disposed between the cathode chamber portion and the anode chamber portion; and

a gas permeable membrane disposed in proximity to the channel that minimizes a passage of the fluid therethrough and allows the passage of a gas byproduct.

9. The apparatus according to claim 6 wherein the catalytic recombiner recombines oxygen and hydrogen.

10. The apparatus according to claim 9 wherein the gas byproduct is hydrogen and the channel allows the hydrogen disposed in the cathode chamber portion to pass to the anode chamber portion.

11. A method of making a portion of an electroosmotic pump comprising:

forming a plastic frame containing an open chamber therein, by attaching together a plurality of plastic pieces, the open chamber being separated into first and second chamber portions at least partially by a porous dielectric disposed within the plastic frame;

attaching the porous dielectric to the frame using epoxy;

integrating a catalytic recombiner with the open chamber; and

attaching a gas permeable membrane to a surface of the catalytic recombiner.

12. An electroosmotic pump that pumps a fluid having a liquid phase upon application of a voltage comprising:

a fluid chamber having a fluid inlet and a fluid outlet;

an anode disposed within an anode chamber portion;

first and second cathodes disposed within respective first and second cathode chamber portions; and

first and second porous structures that provide electroosmotic pumping upon application of the voltage between the anode and the first and second cathodes, each of the first and second porous structures creating a partition in the fluid chamber between the anode chamber portion and the respective cathode chamber portions.

13. The electroosmotic pump according to claim 12 further including a catalytic recombiner.

14. The apparatus according to claim 13 wherein the catalytic recombiner recombines oxygen and hydrogen.

15. The apparatus according to claim 14 wherein the gas byproduct is hydrogen and the channel allows the hydrogen disposed in the cathode chamber portions to pass to the anode chamber portion.

16. The electroosmotic pump according to claim 13 further including a heating element disposed in proximity to the catalytic recombiner.

17. The electroosmotic pump according to claim 13 further including:

a first channel disposed between the first cathode chamber portion and the anode chamber portion;

a first gas permeable membrane disposed in proximity to the first channel that minimizes a passage of the fluid therethrough and allows the passage of a gas byproduct;

a second channel disposed between the second cathode chamber portion and the anode chamber portion; and

a second gas permeable membrane disposed in proximity to the second channel that minimizes a passage of the fluid therethrough and allows the passage of the gas byproduct.

18. The apparatus according to claim 17 further including a heating element disposed in proximity to the catalytic recombiner.

19. The apparatus according to claim 18 further including another gas permeable membrane that covers the catalytic recombiner to keep it dry.

20. The apparatus according to claim 17 further including another gas permeable membrane that covers the catalytic recombiner to keep it dry.