Apparatus for manipulating droplets

• US 8,147,668 B2
• Filed: 10/23/2006
• Issued: 04/03/2012
• Est. Priority Date: 09/24/2002
• Status: Active Grant

• Current Assignee: Duke University
• Original Assignee: Duke University
• Inventors: Pollack, Michael G., Pamula, Vamsee K., Fair, Richard B., Ren, Hong
• Primary Examiner(s): SOOHOO, TONY GLEN
• Application Number:
  US11/585,618
• Publication Number:
  US 20070045117A1
• Time in Patent Office: 1,989 Days
• Field of Search: 204/547, 204/643, 204/672, 366/341, 366/DIG.4
• US Class Current: 204/547
• 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: B01F 33/30351 using hydrophilic/hydrophobic surfaces
• CPC Class Codes: B01J 2219/00479 Means for mixing reactants or products in the reaction vessels
• 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 2300/165 Specific details about hydrophobic, oleophobic surfaces
• 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: G01N 15/14 Optical investigation techniques, e.g. flow cytometry
• CPC Class Codes: G01N 2035/1046 Levitated, suspended drops
• CPC Class Codes: G02B 26/005 based on electrowetting
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/113332 with conveyance of sample along a test line in a container or rack
• CPC Class Codes: Y10T 436/117497 with a continuously flowing sample or carrier stream
• CPC Class Codes: Y10T 436/118339 with formation of a segmented stream
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/25625 Dilution
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

Apparatuses for mixing droplets, such as a binary mixing apparatus, are provided. The binary mixing apparatus includes an array of electrodes and a conducting element positioned in relation to at least one of the electrodes to enable a droplet placed in electrical communication with the at least one electrode to electrically communicate with the conducting element. The binary mixing apparatus additionally includes an electrode selector for sequentially biasing one or more selected electrodes of the array to move a droplet disposed on the array into contact with another droplet. The apparatus further includes a first droplet supply area communicating with the array and a second droplet supply area communicating with the array.

Claims

1. An apparatus comprising:

(a) a first substrate and a second substrate separated from one another to form a gap therebetween, the gap comprising oil, wherein at least one of the first substrate and second substrate comprises;

(i) an array of drive electrodes, wherein the array of drive electrodes are configured for conducting electrowetting mediated droplet operations in the gap;

(ii) a conducting element comprising a conducting line grid comprising electrically intersecting conducting lines adjacent to the drive electrodes, wherein the electrically intersecting conducting lines form a single electrical element set at a common reference potential;

(iii) a dielectric layer covering the drive electrodes, and a hydrophobic layer covering the drive electrodes and the conducting element, wherein the dielectric layer and the hydrophobic layer do not electrically isolate the conducting element from a droplet when formed thereon;

(b) an electrode selector electrically configured to bias one or more selected ones of the drive electrodes of the array;

(c) a first liquid supply area communicating with the array;

(d) a second liquid supply area communicating with the array; and

(e) drive electrodes located respectively at said first sample liquid supply area and at said second liquid supply area for being energized to form droplets from said respective liquid supply areas into the gap.

2. The apparatus of claim 1 wherein the electrode selector comprises a processor.

3. The apparatus of claim 1 wherein the hydrophobic layer covering the conducting element is sufficiently thin to permit electrical contact between the droplet and the conducting element.

4. The apparatus of claim 1 wherein the dielectric layer has a permittivity and thickness, and the biasing comprises applying a voltage to energize a drive electrode, and the permittivity, thickness, and a voltage supply are selected to produce droplet movement by electrowetting for a droplet formed for conducting droplet operations with the apparatus.

5. The apparatus of claim 1 wherein the conducting element is substantially coplanar with the array of drive electrodes.

6. The apparatus of claim 1 wherein the conducting element is coplanar with the array of drive electrodes.

7. The apparatus of claim 1 wherein the conducting element comprises conductive interconnect structures.

8. The apparatus of claim 1 wherein the conducting element comprises conducting lines positioned in relation to a first one of the drive electrodes such that a droplet atop the first one of the drive electrodes having a size which causes it to partially overlap an adjacent one of the drive electrodes electrically communicates an intervening conducting element.