Apparatus and method for using electrostatic force to cause fluid movement

• US 20030183525A1
• Filed: 04/01/2002
• Published: 10/02/2003
• Est. Priority Date: 04/01/2002
• Status: Active Grant

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Bell, Alan G., Peeters, Eric, Torres, Francisco E., Biegelsen, David K., Elrod, Scott A., Dunec, John L.
• Granted Patent: US 7,147,763 B2
• Time in Patent Office: Days
• US Class Current: 204/547
• CPC Class Codes: B01F 25/14 Mixing drops, droplets or bodies of liquid which flow together or contact each other micromixers using where the materials to be mixed are in the form of droplets B01F33/302
• CPC Class Codes: B01F 33/3021 the components to be mixed being combined in a single independent droplet, e.g. these droplets being divided by a non-miscible fluid or consisting of independent droplets
• CPC Class Codes: B01F 33/3031 using electro-hydrodynamic [EHD] or electro-kinetic [EKI] phenomena to mix or move the fluids
• CPC Class Codes: B01J 2219/0036 Nozzles
• CPC Class Codes: B01J 2219/00527 Sheets
• CPC Class Codes: B01J 2219/00653 the compounds being bound to electrodes embedded in or on the solid supports
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: C40B 60/14 for creating libraries
• CPC Class Codes: G02B 26/005 based on electrowetting

Abstract

A device for effecting motion of liquid droplets on a surface through the use of electrostatic field force includes a single substrate on which are disposed a plurality of spaced-apart electrodes. A dielectric material surrounds the electrodes on the substrate. The surface on which the liquid droplets are deposited is fabricated from a material that facilitates motion of the liquid droplets.

Claims

8. A method for effecting motion of liquid droplets on a surface of an apparatus having a single substrate, a plurality of electrodes disposed on the substrate and spaced one from another, a dielectric layer disposed on the substrate and the electrodes, and a surface comprised of a suitable material for facilitating motion of the liquid droplets, wherein motion of the droplets is effected through the use of electrostatic field force, comprising:

depositing not less than one droplet on the surface; and

applying a voltage between not less than two electrodes of the plurality of electrodes disposed on the substrate.

1. An apparatus for effecting motion of liquid droplets on a surface through the use of electrostatic field force, comprising:

a single substrate;

a plurality of electrodes disposed on said substrate and spaced one from another;

a dielectric layer disposed adjacent to said substrate and surrounding said electrodes; and

a surface comprised of a suitable material for facilitating motion of the liquid droplets.

2. The apparatus for effecting motion of liquid droplets on a surface according to claim 1, wherein said surface is disposed on said dielectric layer.

3. The apparatus for effecting motion of liquid droplets on a surface according to claim 1, wherein said plurality of electrodes comprises not less than two electrodes.

4. The apparatus for effecting motion of liquid droplets on a surface according to claim 1, wherein said plurality of electrodes comprises interdigitated electrode fingers.

5. The apparatus for effecting motion of liquid droplets on a surface according to claim 1, wherein said dielectric layer further comprises an insulating layer.

6. The apparatus for effecting motion of liquid droplets on a surface according to claim 1, wherein said surface comprises a hydrophobic surface.

7. The apparatus for effecting motion of liquid droplets on a surface according to claim 1, wherein said surface comprises an oleophobic surface.

9. The method for effecting motion of liquid droplets according to claim 8, wherein the step of depositing not less than one droplet on the surface comprises depositing said droplet such that said droplet asymmetrically bridges the gap between at least two of said electrodes.

10. The method for effecting motion of liquid droplets according to claim 8, wherein the step of depositing not less than one droplet on the surface comprises depositing said droplet such that said droplet symmetrically bridges the gap between at least two of said electrodes.

11. The method for effecting motion of liquid droplets according to claim 8, further comprising moving the droplet across the surface disposed on the dielectric layer by successively applying a voltage between a succession of electrodes.

12. The method for effecting motion of liquid droplets according to claim 8, wherein said succession of adjacent electrodes comprises not less than three electrodes.

13. The method for effecting motion of liquid droplets according to claim 8, wherein said succession of adjacent electrodes comprises a plurality of electrodes.

14. The method for effecting motion of liquid droplets according to claim 8, further comprising merging not less than two droplets.

15. The method for effecting motion of liquid droplets according to claim 14, wherein merging said not less than two droplets comprises moving and/or deforming not less than one droplet so as to contact not less than one other droplet.

16. The method for effecting motion of liquid droplets according to claim 14, further comprising merging not less than two droplets having not less than one differing properties, with sufficient velocity to effect mixing within a merged droplet.

17. The method for effecting motion of liquid droplets according to claim 14, wherein said not less than two droplets are of dissimilar size.

18. The method for effecting motion of liquid droplets according to claim 14, wherein said merging produces a chemical reaction within not less than one merged droplet.

19. The method for effecting motion of liquid droplets according to claim 14, wherein the surface comprises a source site and a target site.

20. The method for effecting motion of liquid droplets according to claim 8, wherein depositing not less than two droplets on the surface comprises depositing said droplets such that at least one said droplet asymmetrically bridges the gap between at least two said adjacent electrodes.

21. The method for effecting motion of liquid droplets according to claim 8, wherein depositing not less than two droplets on the surface comprises depositing said droplets such that at least one said droplet symmetrically bridges the gap between at least two said electrodes.

22. The method for effecting motion of liquid droplets according to claim 8, wherein depositing not less than two droplets on the surface comprises depositing said droplets such that at least one said droplet is disposed in close proximity to a droplet covering at least part of each of two said electrodes.

23. The method for effecting motion of liquid droplets according to claim 11, wherein said succession of adjacent electrodes comprises an interdigitated set of electrode fingers.

24. The method for effecting motion of liquid droplets according to claim 8, wherein the surface comprises a micro-calorimeter.

25. The method for effecting motion of liquid droplets according to claim 8, wherein the surface comprises a hydrophobic surface.

26. The method for effecting motion of liquid droplets according to claim 8, wherein the surface comprises an oleophobic surface.

27. The method for effecting motion of liquid droplets according to claim 8, wherein the effected motion comprises deformation of not less than one droplet.

28. The method for effecting motion of liquid droplets according to claim 8, wherein the effected motion comprises movement of not less than one droplet from a first location on the surface to a second location on the surface.

15-1. The method for effecting motion of liquid droplets according to claim 14, wherein merging said not less than two droplets comprises moving and/or deforming not less than one droplet so as to contact not less than one other droplet.

16-2. The method for effecting motion of liquid droplets according to claim 14, further comprising merging not less than two droplets having not less than one differing properties, with sufficient velocity to effect mixing within a merged droplet.

17-3. The method for effecting motion of liquid droplets according to claim 14, wherein said not less than two droplets are of dissimilar size.

18-4. The method for effecting motion of liquid droplets according to claim 14, wherein said merging produces a chemical reaction within not less than one merged droplet.

19-5. The method for effecting motion of liquid droplets according to claim 14, wherein the surface comprises a source site and a target site.

20-6. The method for effecting motion of liquid droplets according to claim 8, wherein depositing not less than two droplets on the surface comprises depositing said droplets such that at least one said droplet asymmetrically bridges the gap between at least two said adjacent electrodes.