Microwave microfluidics

• US 8,309,367 B2
• Filed: 04/14/2005
• Issued: 11/13/2012
• Est. Priority Date: 10/03/2000
• Status: Active Grant

• Current Assignee: Mirari Biosciences, Inc.
• Original Assignee: Mirari Biosciences, Inc.
• Inventors: Saul, Richard, Martin, Mark T.
• Primary Examiner(s): Shibuya, Mark
• Assistant Examiner(s): DO, PENSEE T
• Application Number:
  US11/105,460
• Publication Number:
  US 20050191708A1
• Time in Patent Office: 2,770 Days
• Field of Search: 436/518, 436/173, 436/50, 436/51, 436/806, 436/149
• US Class Current: 436/518
• CPC Class Codes: B01J 19/126 Microwaves
• CPC Class Codes: B01J 2219/0871 Heating or cooling of the reactor
• CPC Class Codes: B01J 2219/0879 Solid
• CPC Class Codes: C12N 11/00 Carrier-bound or immobilised enzymes; Carrier-bound or immobilised microbial cells; Preparation thereof
• CPC Class Codes: C12N 13/00 Treatment of microorganisms or enzymes with electrical or wave energy, e.g. magnetism, sonic waves
• CPC Class Codes: G01N 1/44 Sample treatment involving radiation, e.g. heat
• CPC Class Codes: G01N 33/5436 with ligand physically entrapped within the solid phase liposomes G01N33/5432; immunological test elements G01N33/54386
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property
• CPC Class Codes: Y10T 436/115831 Condition or time responsive
• CPC Class Codes: Y10T 436/116664 with automated titrator
• CPC Class Codes: Y10T 436/24 Nuclear magnetic resonance, electron spin resonance or other spin effects or mass spectrometry

Abstract

The present invention concerns a novel means by which liquids can be moved or mixed. Microwaves strike and heat materials that are highly susceptible to microwave heating. The susceptible materials are on, within, or near materials that melt or change shape in response to temperature increases. Upon microwave irradiation, these materials change shape (e.g., shrink or melt), causing the movement of liquids. The invention is important in many microfluidics applications, especially in biomedical analysis, where it is valuable to be able to move small volumes of liquids (e.g., on a microarray chip).

Claims

1. A method for moving a fluid or object comprising;

(a) providing a composite comprised of at least a first material, and a second material that is in thermal proximity to the first material, wherein the first material increases in temperature upon absorption of electromagnetic radiation and the second material melts or changes shape upon heat transfer;

(b) placing the composite in contact with said fluid or object;

(c) thereafter applying electromagnetic radiation to the composite allowing said first material to undergo a temperature change sufficient to cause said second material to melt or change shape, wherein such melting or changing shape of the second material causes a change of position of the second material thereby causing movement of said fluid or object, wherein the wavelength of said applied electromagnetic radiation is between 5 cm and 100 m.

2. The method of claim 1, wherein the change of position of the second material applies a change of force on the fluid or object thereby causing said movement thereof.

3. The method of claim 1, wherein the change of position of the second material allows a force applied to the fluid or object to cause said movement thereof.

4. The method of claim 3, wherein the applied force is gravity and the composite is applying a force equal and opposite to the force of gravity until the second material melts or changes shape, such that the fluid or object thereby moves under the force of gravity.

5. The method of claim 3, wherein the applied force is external and the composite is applying a force equal and opposite to the external force until the second material melts or changes shape, such that the fluid or object thereby moves in response to the external force.

6. The method of claim 5, wherein the external force is selected from the group consisting of hydraulic, pneumatic, spring, vacuum, capillary, and wicking.

7. The method of claim 1, wherein the composite is an elongated substrate and the step of applying electromagnetic radiation to the composite is in an area on the substrate proximal to the fluid or object to cause movement of the fluid object from a first position on the substrate to a second position on the substrate.

8. The method of claim 1, wherein said first material contains one or more material(s) selected from the group consisting of carbon, clay, BaTiO₃, inorganic titanates, inorganic niobates, ferroelectric polymers, Al₂O₃—

Fe₃O₄, Fe₃O₄, organic polymers, aluminum-epoxy composites, silicon oxides, LaCoO₃, LaSrO₃, LaMnO₃, LaFeO₃, SiC, AlN, ZnO, MgO—

SiC, Al₂O₃, AlN—

SiC, CrB, Fe₂B, SiC/SiO₂, alumina, mullite, zircon, MgO, Si₃N₄, Si, Mg, FeSi, Cr₂O₃, MgO, MnO₂, NiO, calcium aluminate, ITO, Nb, TaC, SiC, MoSi₂, Cu, Fe, ZrO₂, Y₂O₃, zirconium oxynitrate, aluminum nitrate, yttrium nitrate, and ferrites.

9. The method of claim 1, wherein said second material contains one or more material(s) selected from the group consisting of polyolefin, fluoropolymer, chlorinated polyolefin, highly flexible elastomer, wax, lipid, and phospholipid.

10. The method of claim 1, wherein the fluid is an aqueous or organic liquid.

11. The method of claim 1, wherein said temperature change is between 1°

C. and 200°

C.

12. The method of claim 1, wherein the direction of the fluid movement is linear, branched, expanding planar, or expanding spherical.

13. The method of claim 1, wherein said fluid movement initiates a chemical reaction involving one or more solutes of said fluid.

14. The method of claim 1, wherein said fluid movement initiates a chemical reaction involving one or more solutes in said fluid, and in which the extent or rate of said chemical reaction can be measured.

15. The method of claim 1, wherein the second material does not substantially increase in temperature by absorbing electromagnetic radiation.