Electokinetic high pressure hydraulic system

• US 6,013,164 A
• Filed: 06/25/1997
• Issued: 01/11/2000
• Est. Priority Date: 06/25/1997
• Status: Expired due to Term

• Current Assignee: MAIL STOP 9007
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Paul, Phillip H., Rakestraw, David J.
• Primary Examiner(s): Phasge, Arun S.
• Application Number:
  US08/882,725
• Time in Patent Office: 930 Days
• Field of Search: 204/450, 204/600, 204/647, 204/648
• US Class Current: 204/450
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: G01N 2030/285 electrically driven carrier
• CPC Class Codes: G01N 2030/326 pumps
• CPC Class Codes: G01N 30/32 of pressure or speed G01N30/36 takes precedence

Abstract

A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.

Claims

1. A valve for the manipulation of a fluid, comprising:

a) a microchannel having an inlet and an outlet and a porous dielectric material disposed therebetween;

b) at least one fluid inlet and fluid outlet in communication with the outlet of said microchannel;

c) an electrolyte contained within the porous dielectric material said electrolyte being selectively moveable between a first position opening communication between the fluid inlet and the fluid outlet and a second position closing communication between the fluid inlet and the fluid outlet; and

d) spaced electrodes for moving said electrolyte between the first and second positions.

2. The valve of claim 1, wherein said microchannel has a circular cross-section.

3. The valve of claim 1, wherein said microchannel comprises a fused silica capillary.

4. The valve of claim 1, wherein the porous dielectric material includes silica particles.

5. The valve of claim 4, wherein the silica particles have a diameter of between about 100 nm and 5 μ

m.

6. The valve of claim 1, wherein the porous dielectric material includes porous dielectric materials fabricated by processes selected from the group consisting of lithographic patterning and etching, direct injection molding, sol-gel processing, and electroforming.

7. The valve of claim 1, wherein the porous dielectric material includes organic polymer materials.

8. The valve of claim 1, wherein the fluid is a gas.

9. A method for manipulating a flow of a fluid, comprising:

applying an electric potential to spaced electrodes in communication with an electrolyte contained within a porous dielectric disposed within a microchannel, thereby causing the electrolyte to move from a first position, wherein a fluid inlet and a fluid outlet are in open communication, to a second position closing communication between the fluid inlet and outlet; and

shutting off the electric potential, thereby causing the electrolyte to move to the first position.

10. The method of claim 9, wherein the fluid is a gas.

11. The method claim 9, wherein said step of applying includes applying an electric potential that varies in time.

12. A system for compressing a fluid, comprising:

a) a microchannel having an inlet and an outlet and a porous dielectric material disposed therebetween;

b) an electrolyte contained within said microchannel;

c) spaced electrodes in communication with said electrolyte; and

d) at least one flow channel in communication with the outlet of said microchannel, wherein said flow channel contains a fluid and is provided with at least one fluid inlet and one fluid outlet configured such that when an electro-osmotic force is applied to said electrolyte the fluid is compressed.

13. The system of claim 12, wherein said microchannel has a circular cross-section.

14. The system of claim 12, wherein said microchannel and flow channel each comprise a fused silica capillary.

15. The system of claim 12, wherein the porous dielectric material includes silica particles.

16. The system of claim 15, wherein the silica particles have a diameter of between about 100 nm and 5 μ

m.

17. The system of claim 12, wherein the porous dielectric material includes porous dielectric materials fabricated by processes selected from the group consisting of lithographic patterning and etching, direct injection molding, sol-gel processing, and electroforming.

18. The system of claim 12, wherein the porous dielectric includes organic polymer materials.

19. A method for compressing a liquid or a gas, comprising:

applying an electric potential to spaced electrodes in communication with an electrolyte contained within a porous dielectric disposed within a microchannel having one end sealed, thereby to cause the electrolyte to move compressing a fluid contained between the electrolyte and the sealed end; and

shutting of the electric potential to release the pressure on the fluid.

20. The method of claim 19, wherein the step of shutting includes reversing the electric potential.

21. An apparatus for the manipulation of a fluid, consisting of:

a) a flow channel for passage of a fluid having an inlet and an outlet, wherein the inlet and outlet ends are disposed at an angle to each other; and

b) means for generating an electro-osmotic force in communication with the inlet end of said flow channel.

22. An apparatus for compressing a fluid, consisting of:

a) a flow channel for passage of a fluid having an inlet and an outlet, wherein the outlet end of said channel is constricted; and

b) means for generating an electro-osmotic force in communication with the inlet end of said flow channel.