Electrokinetic micro-fluid mixer

• US 6,086,243 A
• Filed: 10/01/1998
• Issued: 07/11/2000
• Est. Priority Date: 10/01/1998
• Status: Expired due to Term

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Paul, Phillip H., Rakestraw, David J.
• Primary Examiner(s): SOOHOO, TONY GLEN
• Application Number:
  US09/164,863
• Time in Patent Office: 649 Days
• Field of Search: 366/273, 366/336, 366/340, 366/274, 366/173.1, 366/167.1, 366/349, 366/341, 366/348, 204/451, 204/453, 204/454, 204/450
• US Class Current: 366/273
• CPC Class Codes: B01F 25/31 in conduits or tubes through which the main component flows
• CPC Class Codes: B01F 33/05 Mixers using radiation, e.g. magnetic fields or microwaves to mix the material B01F23/2133, B01F23/238, B01F23/55, B01F33/3031, B01F33/3032 take precedence
• CPC Class Codes: B01F 33/3031 using electro-hydrodynamic [EHD] or electro-kinetic [EKI] phenomena to mix or move the fluids
• CPC Class Codes: B01F 33/3032 using magneto-hydrodynamic [MHD] phenomena to mix or move the fluids
• CPC Class Codes: B01F 35/7172 using capillary forces
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 2219/00853 Employing electrode arrangements
• CPC Class Codes: B01J 2219/00889 Mixing micromixers B01F33/30
• CPC Class Codes: Y10S 366/04 Micromixers: with application of energy to influence mixing/agitation, e.g. magnetic, electrical, e-m radiation, particulate radiation, or ultrasound

Abstract

A method and apparatus for efficiently and rapidly mixing liquids in a system operating in the creeping flow regime such as would be encountered in capillary-based systems. By applying an electric field to each liquid, the present invention is capable of mixing together fluid streams in capillary-based systems, where mechanical or turbulent stirring cannot be used, to produce a homogeneous liquid.

Claims

1. A method for mixing liquids, comprising:

a) providing a chamber, at least partially fabricated from a dielectric material, and having separate capillary inlets;

b) flowing liquids to be mixed into the chamber through each capillary inlet, wherein the liquids are flowing in a creeping flow regime;

c) applying a voltage between pairs of spaced electrodes disposed on the dielectric material of the chamber, wherein each pair of spaced electrodes is in contact with one liquid, thereby subjecting each liquid to a substantially tangential electric field and electroosmotic flow to cause the different liquids to mix together; and

d) causing the mixed liquid to exit from the chamber.

2. The method of claim 1, wherein said step of applying includes applying a voltage that varies in time.

3. An apparatus for mixing liquids, comprising:

a) a chamber, at least partially fabricated from a dielectric material, and having separate capillary inlets for flowing liquids into said chamber, wherein the liquids flowing into said chamber flow in a creeping flow regime;

b) pairs of spaced electrodes disposed on the dielectric material, wherein each pair of spaced electrodes is arranged to be in contact with each liquid;

c) means for supplying DC power to each pair of electrodes; and

d) a liquid outlet to direct the outflow from said chamber.

4. The apparatus of claim 3, wherein the chamber is made from a dielectric material having a conductivity less than that of the introduced liquids.

5. The apparatus of claim 4, wherein the dielectric material is selected from the group consisting of silica and alumina.

6. The apparatus of claim 4, further including two or more chambers connected in series.

7. The apparatus of claim 4, further including two or more chambers connected in parallel.