Electrostatic actuators for microfluidics and methods for using same

• US 6,773,566 B2
• Filed: 08/30/2001
• Issued: 08/10/2004
• Est. Priority Date: 08/31/2000
• Status: Expired due to Term

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Nanolytics, Inc. (Illumina Incorporated)
• Inventors: Shenderov, Alexander
• Primary Examiner(s): Phasge, Arun S.
• Application Number:
  US09/943,675
• Publication Number:
  US 20020043463A1
• Time in Patent Office: 1,076 Days
• Field of Search: 204/450, 204/600
• US Class Current: 204/450
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/0829 Multi-well plates; Microtitration plates
• CPC Class Codes: B01L 2300/0874 Three dimensional network
• 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 3/502784 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: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence

Abstract

An apparatus for inducing movement of an electrolytic droplet includes: a housing having an internal volume filled with a liquid immiscible with an electrolytic droplet; a distribution plate positioned within the chamber having an aperture and dividing the housing into upper and lower chambers; a lower electrode positioned below the lower chamber and the aperture in the distribution plate and being separated from the lower chamber by an overlying hydrophobic insulative layer; an upper electrode located above the upper chamber and the aperture of the distribution plate and being separated from the upper chamber by an underlying hydrophobic insulative layer; and first, second and third voltage generators that are electrically connected to, respectively, the lower and upper electrodes and the distribution plate. The voltage generators are configured to apply electrical potentials to the lower and upper electrodes and the distribution plate, thereby inducing movement of the electrolytic droplet between the hydrophobic layers.

Claims

1. An apparatus for inducing movement of an electrolytic droplet, comprising:

a housing having an internal volume filled with a liquid immiscible with an electrolytic droplet;

a distribution plate positioned within the chamber having an aperture therein, the distribution plate dividing the housing into upper and lower chambers;

a lower electrode positioned below the lower chamber and below the aperture in the distribution plate, the lower electrode being electrically insulated from the lower chamber and being separated from the lower chamber by an overlying hydrophobic layer;

an upper electrode located above the upper chamber and above the aperture of the distribution plate, the upper chamber electrode being electrically insulated from the upper chamber and being separated from the upper chamber by an underlying hydrophobic layer; and

first, second and third voltage generators that are electrically connected to, respectively, the lower and upper electrodes and the distribution plate, the first, second and third second voltage generators being configured to apply electrical potentials thereto, thereby inducing movement of the electrolytic droplet between the hydrophobic layers of the upper and lower chambers.

2. The apparatus defined in claim 1, wherein the distribution plate comprises a conductive outer layer.

3. The apparatus defined in claim 1, wherein the first, second and third voltage generators are coincident.

4. The apparatus defined in claim 1, wherein the upper chamber hydrophobic layer is coated with a reactive substrate.

5. The apparatus defined in claim 4, wherein the reactive substrate is selected from the group consisting of:

antibodies, receptors, ligands, nucleic acids, polysaccharides, and proteins.

6. An apparatus for inducing movement of an electrolytic droplet, comprising:

a housing having an internal volume filled with a liquid immiscible with an electrolytic droplet;

a distribution plate positioned within the chamber having an aperture therein, the distribution plate dividing the housing into upper and lower chambers;

a lower electrode positioned below the lower chamber and below the aperture in the distribution plate, the lower electrode being separated from the lower chamber by an overlying hydrophobic layer;

an upper electrode located above the upper chamber and above the aperture of the distribution plate, the upper chamber electrode being separated from the upper chamber by an underlying hydrophobic layer;

a plurality of adjacent, electrically isolated droplet manipulation electrodes positioned above the lower electrode and below the lower chamber hydrophobic layer, wherein sequential droplet manipulation electrodes have substantially contiguous, hydrophobic upper surfaces that define a droplet travel path, wherein one of the lower droplet manipulation electrodes is positioned below the aperture in the distribution plate;

first, second and third voltage generators that are electrically connected to, respectively, the lower and upper electrodes and the distribution plate, the first, second and third second voltage generators being configured to apply electrical potentials thereto, thereby inducing movement of the electrolytic droplet between the hydrophobic layers of the upper and lower chambers; and

a fourth voltage generator that is electrically connected to the plurality of droplet manipulation electrodes and is configured to apply electrical potentials sequentially to the droplet manipulation electrodes along the droplet travel path, thereby inducing movement of the electrolytic droplet along the droplet travel path.

7. The apparatus defined in claim 6, wherein the distribution plate comprises a conductive outer layer.

8. The apparatus defined in claim 6, wherein the upper chamber hydrophobic surface is coated with a reactive substrate to form a reaction site.

9. The apparatus defined in claim 8, wherein the reactive substrate is selected from the group consisting of:

antibodies, receptors, ligands, nucleic acids, polysaccharides, and proteins.

10. The apparatus defined in claim 6, further comprising an inlet fluidly connected with the bottom chamber that provides access thereto, the inlet being positioned above one of the plurality of lower chamber electrodes.

11. The apparatus defined in claim 6, wherein the upper hydrophobic layer is substantially transparent.

12. The apparatus defined in claim 6, wherein at least two adjacent ones of the plurality of droplet manipulation electrodes include noncontacting interdigitating projections in their adjacent edges.

13. The apparatus defined in claim 6, wherein the distribution plate includes a plurality of apertures, and wherein the upper chamber hydrophobic surface is coated in a plurality of locations with a reactive substrate to form a plurality of reaction sites, and each of the distribution plate apertures is substantially vertically aligned with a respective droplet manipulation electrode and a respective reaction site.

14. A method of moving an electrolytic droplet, comprising:

providing a housing having an internal volume and a distribution plate residing therein, the distribution plate having an aperture and dividing the internal volume into upper and lower chambers, the lower chamber including an electrolytic droplet and each of the upper and lower chambers containing a liquid immiscible with the electrolytic droplet, the housing including a lower electrode electrically insulated from the lower chamber and underlying a hydrophobic layer, and the housing further including an upper electrode electrically insulated from the upper chamber and overlying a hydrophobic lower layer;

positioning the electrolytic droplet above the lower electrode and beneath the distribution plate aperture; and

applying electrical potentials to the lower and upper electrodes and to the distribution plate to draw the electrolytic droplet through the distribution plate aperture and to the upper chamber hydrophobic surface.

15. The method defined in claim 14, wherein the distribution plate is coated with a conductive material.

16. The method defined in claim 15, further comprising maintaining the electrolytic droplet in contact with the reaction site for a preselected duration sufficient to enable the reaction between the constituents of the electrolytic droplet and the reactive substrate to reach completion.

17. The method defined in claim 14, wherein the upper chamber hydrophobic surface is coated with a reactive substrate to form a reaction site, and wherein contact between the electrolytic droplet and the reaction site causes a reaction between constituents of the electrolytic droplet and the reactive substrate.

18. The method defined in claim 17, wherein the reactive substrate is selected from the group consisting of:

antibodies, receptors, ligands, nucleic acids, polysaccharides, and proteins.

19. An apparatus for inducing movement of an electrolytic droplet, comprising:

a housing having an internal volume;

a plurality of adjacent, electrically isolated transport electrodes positioned in the housing, wherein sequential transport electrodes have substantially contiguous, hydrophobic surfaces, the transport electrodes defining a droplet travel path;

a first voltage generator electrically connected to the transport electrodes, the first voltage generator configured to apply electrical potentials sequentially to each transport electrode along the droplet travel path, thereby inducing movement of an electrolytic droplet along the travel path;

a plurality of gate electrodes, each of the gate electrodes positioned in the housing adjacent a respective transport electrode and having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent transport electrode, the gate electrodes being electrically connected;

a second voltage generator connected to the plurality of gate electrodes and configured to apply electrical potentials thereto;

a plurality of destination electrodes, each of which is positioned in the housing adjacent a respective gate electrode, each destination electrode having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent gate electrode; and

a third voltage generator connected to the destination electrodes and configured to apply electrical potentials thereto.

20. A method of inducing movement in an electrolytic drop, comprising:

providing a device comprising;

a housing having an internal volume filled with a liquid immiscible with an electrolytic droplet;

a plurality of adjacent, electrically isolated transport electrodes positioned in the housing, wherein sequential transport electrodes have substantially contiguous, hydrophobic surfaces, the transport electrodes defining a droplet travel path;

a plurality of gate electrodes, each of the gate electrodes positioned in the housing adjacent a respective transport electrode and having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent transport electrode, the gate electrodes being electrically connected; and

a plurality of destination electrodes, each of which is positioned in the housing adjacent a respective gate electrode, each destination electrode having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent gate electrode;

positioning an electrolytic droplet on a first transport electrode;

applying an electrical potential to a second transport electrode adjacent the first transport electrode sufficient to induce the electrolytic droplet to move from the first transport chamber electrode to the second transport electrode;

repeating the applying step to continue inducing movement of the electrolytic droplet between adjacent lower chamber electrodes along the droplet travel path to a predetermined transport adjacent a first gate electrode, wherein the first gate electrode is at a ground state;

applying an electrical potential to the first gate electrode as the predetermined transport electrode is at a ground state to induce the electrolytic droplet to move from the predetermined transport electrode to the first gate electrode, wherein a first destination electrode adjacent the first gate electrode is in a ground state; and

applying an electrical potential to the first destination electrode as the first gate electrode is in a ground state to induce the electrolytic droplet to move from the first gate electrode to the first destination electrode.

21. The method defined in claim 20, further comprising contacting the electrolytic droplet with a reactive substrate after the electrolytic substrate moves to the first destination electrode.

22. The method defined in claim 21, wherein contacting the electrolytic droplet with a reactive substrate comprises contacting the electrolytic droplet to an electrode having a hydrophobic surface coated with the reactive substrate.