Droplet actuator configurations and methods of conducting droplet operations

• US 9,630,180 B2
• Filed: 01/06/2015
• Issued: 04/25/2017
• Est. Priority Date: 12/23/2007
• Status: Expired due to Fees

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Inventors: Srinivasan, Vijay, Pollack, Michael G., Pamula, Vamsee K., Hua, Zhishan, Sudarsan, Arjun, Paik, Philip Y.
• Primary Examiner(s): Gordon, Brian R
• Application Number:
  US14/590,470
• Publication Number:
  US 20150174578A1
• Time in Patent Office: 840 Days
• Field of Search: 422501-502, 204600-604, 204450-453
• 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 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2200/143 Quality control, feedback systems
• 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 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 2400/06 Valves, specific forms thereof
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/0241 Drop counters; Drop formers making arrays for combinatorial libraries B01J19/0046; automation of dispensing for analysis G01N35/10
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: B01L 3/52 Containers specially adapted for storing or dispensing a reagent B01L3/02 takes precedence; containers for medical or pharmaceutical purposes A61J1/00; containers in general B65D; storing or dispensing test elements G01N33/4875; automated reagent dispensing G01N35/1002
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence

Abstract

A droplet actuator with a droplet formation electrode configuration associated with a droplet operations surface, wherein the electrode configuration may include one or more electrodes configured to control volume of a droplet during formation of a sub-droplet on the droplet operations surface. Methods of making and using the droplet actuator are also provided.

Claims

1. A droplet actuator comprising:

a top substrate comprising a reservoir integral with the top substrate;

a bottom substrate separated from the top substrate to form a gap;

droplet transport electrodes proximal to the top substrate and/or the bottom substrate in a manner which permits the droplet transport electrodes to conduct one or more electrowetting-mediated droplet transport operations;

a reservoir electrode proximal to the bottom substrate in a manner which permits, in combination with the droplet transport electrodes, a droplet extension to flow out of a volume of fluid at the reservoir electrode, wherein the reservoir electrode is larger than the droplet transport electrodes;

a fluid path comprising an opening in the top substrate and configured for flowing fluid from the reservoir into the gap; and

wherein the opening has a diameter D1 and the reservoir has a diameter D2, and wherein D2 is smaller than D1;

wherein the diameter D1 is at least twice as large as height of the gap; and

wherein the droplet actuator is configured such that fluid flowing through the fluid path flows from the reservoir across the opening into the gap and is positioned as a volume of fluid atop the reservoir electrode until a voltage is applied to one or more of the droplet transport electrodes.

2. The droplet actuator of claim 1 wherein the opening overlaps an edge of the reservoir electrode.

3. The droplet actuator of claim 1 wherein D1 is in a range of about 1 mm to about 2 mm.

4. The droplet actuator of claim 1 wherein D2 is greater than about 1 mm.

5. The droplet actuator of claim 1 wherein the gap height is about 200 um.

6. The droplet actuator of claim 1 wherein the reservoir has a volume sufficient to hold a volume of liquid ranging from about 5 μ

l to about 5000 μ

L.

7. The droplet actuator of claim 1 wherein the reservoir has a volume sufficient to hold a volume of liquid ranging from about 10 μ

L to about 2000 μ

L.

8. The droplet actuator of claim 1 wherein the reservoir has a volume sufficient to hold a volume of liquid ranging from about 50 μ

L to about 1500 μ

L.

9. The droplet actuator of claim 1, wherein the reservoir has dimensions which are substantially cylindrical.

10. The droplet actuator of claim 9 wherein the opening is substantially aligned about an axis of the cylindrical dimensions of the reservoir.

11. The droplet actuator of claim 1, wherein the gap comprises a filler fluid.

12. The droplet actuator of claim 11 wherein the filler fluid comprises an oil.

13. The droplet actuator of claim 1 wherein the droplet actuator is configured such that in response to the voltage applied to the one or more of the droplet transport electrodes, the droplet extension comprising a controlled volume of fluid that is a fraction of the volume of fluid atop the reservoir electrode flows out of the volume of fluid to form a droplet, where the droplet is subjected to the one or more electrowetting-mediated droplet transport operations mediated by the one or more of the droplet transport electrodes.

14. A droplet actuator comprising:

a top substrate comprising a reservoir integral with the top substrate, wherein the reservoir comprises a restricted region having a reduced diameter relative to a main volume region of the reservoir;

a bottom substrate separated from the top substrate to form a gap;

droplet transport electrodes proximal to the top substrate and/or the bottom substrate in a manner which permits the droplet transport electrodes to conduct one or more electrowetting-mediated droplet transport operations;

a reservoir electrode proximal to the bottom substrate in a manner which permits, in combination with the droplet transport electrodes, a droplet extension to flow out of a volume of fluid at the reservoir electrode, wherein the reservoir electrode is larger than the droplet transport electrodes;

a fluid path comprising an opening in the top substrate and configured for flowing fluid from the reservoir into the gap; and

wherein the opening has a diameter D1, the restricted region has a diameter D2, and the main volume region has a diameter D3, and wherein D1 is larger than D2 and D3 is larger than D1;

wherein the diameter D1 is at least twice as large as height of the gap; and

wherein the droplet actuator is configured such that fluid flowing through the fluid path flows from the reservoir across the restricted region and across the opening into the gap and is positioned as a volume of fluid atop the reservoir electrode until a voltage is applied to one or more of the droplet transport electrodes.

15. The droplet actuator of claim 14 wherein the restricted region of the reservoir provides a fluid path between the main volume region of the reservoir and the opening.

16. The droplet actuator of claim 14 wherein D1 is in the range of about 1 mm to about 2 mm.

17. The droplet actuator of claim 14 wherein D2 is about 1.5 mm.

18. The droplet actuator of claim 14 wherein D3 is about 4 mm.

19. The droplet actuator of claim 14 wherein the reservoir further comprises a tapering transition region wherein the reservoir diameter tapers from D3 to D2.

20. The droplet actuator of claim 14 wherein the droplet actuator is configured such that in response to the voltage applied to the one or more of the droplet transport electrodes, a droplet extension comprising a controlled volume of fluid that is a fraction of the volume of fluid atop the reservoir electrode flows out of the volume of fluid to form a droplet, where the droplet is subjected to one or more electrowetting-mediated droplet transport operations mediated by the one or more of the droplet transport electrodes.