Actuators for microfluidics without moving parts

• US 6,565,727 B1
• Filed: 01/24/2000
• Issued: 05/20/2003
• Est. Priority Date: 01/25/1999
• Status: Expired due to Term

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Nanolytics, Inc. (Illumina Incorporated)
• Inventors: Shenderov, Alexander David
• Primary Examiner(s): Tung, T.
• Assistant Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US09/490,769
• Time in Patent Office: 1,212 Days
• Field of Search: 204/600, 204/601, 204/660, 204/672
• US Class Current: 204/600
• CPC Class Codes: B01F 2025/913 Vortex flow, i.e. flow spiraling in a tangential direction and moving in an axial direction
• 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: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0819 Microarrays; Biochips
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• 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 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: B01L 3/502784 specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0017 Capillary or surface tension valves, e.g. using electro-wetting or electro-capillarity effects
• CPC Class Codes: G02B 26/005 : based on electrowetting

Abstract

A series of microactuators for manipulating small quantities of liquids, and methods of using these for manipulating liquids, are disclosed. The microactuators are based on the phenomenon of electrowetting and contain no moving parts. The force acting on the liquid is a potential-dependent gradient of adhesion energy between the liquid and a solid insulating surface.

Claims

1. A device comprising:

a) an electrically non-conductive first solid support having an upper surface;

b) a plurality of first electrodes positioned on said upper surface, each of the first electrodes having at least one edge with projections in interdigitated relationship with projections on an edge of another first electrode;

c) an electrically non-conductive second solid support having a lower surface, positioned opposite to, and separated from, the upper surface of the first solid support, so that a gap is formed between said second and first solid supports;

d) a second electrode positioned on said lower surface;

e) a first electrically insulative, hydrophobic layer insulating said first electrodes from the gap;

f) a second hydrophobic layer positioned between the second electrode and the gap;

g) a droplet comprising a polar liquid positioned in the gap; and

h) a non-polar fluid positioned in the gap.

2. A device according to claim 1, wherein said electrically non-conductive film is made hydrophobic by chemical surface modification.

3. The device defined in claim 1, further comprising a drop meter positioned above a receiving one of the first electrodes, the drop meter being configured to dispense single droplets of the polar liquid onto the receiving first electrode.

4. The device defined in claim 3, wherein the second electrode overlies substantially all of the first electrodes.

5. The device defined in claim 1, wherein the second electrode overlies substantially all of the first electrodes.

6. The device defined in claim 1, wherein the polar liquid is an aqueous solution.

7. The device defined in claim 1, wherein the non-polar fluid is selected from the group consisting of:

air, benzene and silicone oil.

8. A device comprising:

a) an electrically non-conductive first solid support having an upper surface;

b) a plurality of first electrodes positioned on said upper surface;

c) an electrically non-conductive second solid support having a lower surface, positioned opposite to, and separated from, the upper surface of the first solid support, so that a gap is formed between said second and first solid supports;

d) a second electrode positioned on said lower surface;

e) a first electrically insulative, hydrophobic layer insulating said first electrodes from the gap;

f) a second hydrophobic layer positioned between the second electrode and the gap;

g) a droplet comprising a polar liquid positioned in the gap;

h) a non-polar fluid positioned in the gap; and

i) a drop meter positioned above a receiving one of the first electrodes, the drop meter being configured to dispense droplets of the polar liquid onto the receiving first electrode.

9. A device according to claim 8, wherein said electrically non-conductive film is made hydrophobic by chemical surface modification.

10. The device defined in claim 8, wherein the second electrode overlies substantially all of the first electrodes.

11. The device defined in claim 8, wherein the polar liquid is an aqueous solution.

12. The device defined in claim 8, wherein the non-polar fluid is selected from the group consisting of:

air, benzene and silicone oil.