Droplet Actuator with Droplet Retention Structures

• US 20100120130A1
• Filed: 12/28/2009
• Published: 05/13/2010
• Est. Priority Date: 08/08/2007
• Status: Abandoned Application

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Inventors: Sista, Ramakrishna, Pamula, Vamsee K., Thwar, Prasanna, Srinivasan, Vijay
• Application Number:
  US12/647,768
• Publication Number:
  US 20100120130A1
• Time in Patent Office: Days
• US Class Current: 435/283.100
• 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 2200/143 Quality control, feedback systems
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• 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: F16L 55/00 Devices or appurtenances for use in, or in connection with, pipes or pipe systems the preceding groups and groups F16L57/00, F16L59/00 take precedence; repairing or joining pipes on or under water F16L1/26; nozzles B05B; cleaning of pipes B08B9/02; arrangements of draining devices for water main or service pipe systems E03B7/08; devices for preventing bursting of water pipes by freezing E03B7/10; draining devices for hydrants E03B9/14; for domestic plumbing installations E03C1/00; steam traps for draining of liquids from enclosures containing gases or vapours F16T; arrangements for sealing leaky tubes or conduits of heat-exchangers F28F11/00
• CPC Class Codes: Y10T 137/206 Flow affected by fluid contact, energy field or coanda effect [e.g., pure fluid device or system]

Abstract

The present invention is directed to droplet actuators with droplet retention structures, and methods related thereto. In an exemplary embodiment, the invention provides a droplet actuator with one or more substrates arranged to form a droplet operations gap comprising gap-facing surfaces; droplet operations electrodes configured to conduct droplet operations in the droplet operations gap; at least one barrier included on at least one of the substrate surfaces and having dimensions selected to: permit droplet transport from atop a first droplet operations electrode to a second droplet operations electrode when the second droplet operations electrode is activated; and prevent movement of a droplet from atop a first droplet operations electrode when the first and second droplet operations electrodes are inactive.

Claims

1. A droplet actuator comprising:

(a) one or more substrates arranged to form a droplet operations gap comprising gap-facing surfaces;

(b) droplet operations electrodes configured to conduct droplet operations in the droplet operations gap; and

(c) at least one barrier included on at least one of the substrate surfaces and having dimensions selected to;

(i) permit droplet transport from atop a first droplet operations electrode to a second droplet operations electrode when the second droplet operations electrode is activated; and

(ii) prevent movement of a droplet from atop a first droplet operations electrode when the first and second droplet operations electrodes are inactive.

2. The droplet actuator of claim 1 wherein the at least one barrier comprises a physical barrier.

3. The droplet actuator of claim 1 wherein the at least one barrier comprises a chemical barrier.

4. The droplet actuator of claim 1 wherein the at least one barrier comprises a projection from one or more of the gap-facing surfaces.

5. The droplet actuator of claim 1 wherein the at least one barrier comprises a hydrophobic surface.

6. The droplet actuator of claim 4 wherein the projection is formed by embossing the gap-facing surface.

7. The droplet actuator of claim 4 wherein the projection comprises a ridge.

8. The droplet actuator of claim 4 wherein the projection comprises an elevated region surrounding an indentation which is aligned with the first droplet operations electrode.

9. The droplet actuator of claim 1 comprising one or more projections at each edge of a droplet operations electrode.

10. The droplet actuator of claim 1 comprising an array of said first electrodes.

11. The droplet actuator of claim 1, further comprising a feedback and control mechanism for monitoring voltage applied to the droplet operations electrodes, and for controlling the voltage applied to not exceed a minimum level sufficient to carry out selected droplet operations.

12. The droplet actuator of claim 11, wherein the feedback and control mechanism is adapted to detect capacitance from a voltage applied.

13. A method of conducting droplet operations using the droplet actuator of claim 1, the method comprising applying a minimum voltage required to conduct a predetermined droplet operation for maintaining stability of the oil.

14. A method of conducting droplet operations using the droplet actuator of claim 1, the method comprising modulating a voltage used to conduct a predetermined droplet operation for maintaining stability of the oil.

15. A method of conducting droplet operations with the droplet actuator of claim 1, the method comprising limiting the duration of a voltage used to conduct a predetermined droplet operation for maintaining the stability of the oil.

16. A method of conducing droplet operations with the droplet actuator of claim 1, the method comprising monitoring droplet operations and adjusting an electrowetting voltage used to conduct a predetermined droplet operation in response to the monitoring.

17. A method of retaining a droplet in place atop an electrode, the method comprising:

(a) providing a droplet actuator according to claim 1;

(b) providing a droplet in the droplet operations gap atop the second electrode;

(c) activating the first electrode and deactivating the second electrode to cause a droplet to flow onto the first electrode;

(d) deactivating the first electrode and permitting the barrier to retain the droplet atop the first electrode.

18. A kit comprising:

(a) a droplet actuator comprising a droplet operations gap configured for conducting droplet operations;

(b) a sealed container of degassed filler fluid.

19. The kit of claim 18 wherein the sealed container comprises a solidified wax layer arranged to prevent exposure of the degassed filler fluid to the atmosphere.

20. The kit of claim 18 wherein the degassed filler fluid comprises degassed oil.

21. The kit of claim 18 wherein the degassed filler fluid comprises degassed silicone oil.

22. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding room temperature.

23. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 40°

C.

24. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 50°

C.

25. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 60°

C.

26. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 70°

C.

27. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 80°

C.

28. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 90°

C.

29. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature exceeding 40°

C.

30. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature which does not exceed about 150°

C.

31. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature which does not exceed about 110°

C.

32. The kit of claim 18 wherein the droplet actuator is configured for conducting a reaction at a temperature which does not exceed about 100°

C.

33. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 40°

C.

34. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 50°

C.

35. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 60°

C.

36. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 70°

C.

37. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 80°

C.

38. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 90°

C.

39. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature exceeding 40°

C.

40. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature which does not exceed about 150°

C.

41. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature which does not exceed about 110°

C.

42. The kit of claim 18 wherein the kit comprises reagents selected for conducting a reaction at a temperature which does not exceed about 100°

C.

43. The kit of claim 18 wherein the kit comprises nucleic acid amplification reagents.

44. The kit of claim 18 wherein the kit comprises PCR reagents.