Droplet actuators that include molecular barrier coatings

• US 9,223,317 B2
• Filed: 06/12/2013
• Issued: 12/29/2015
• Est. Priority Date: 06/14/2012
• Status: Active Grant

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Inventors: Winger, Theodore
• Primary Examiner(s): Gordon, Brian R
• Application Number:
  US13/915,842
• Publication Number:
  US 20130333762A1
• Time in Patent Office: 930 Days
• US Class Current: 1/1
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• CPC Class Codes: B01L 2300/0681 Filter
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/12 Specific details about materials
• CPC Class Codes: B01L 2300/16 Surface properties and coatings
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 2300/165 Specific details about hydrophobic, oleophobic surfaces
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 3/0268 using pulse dispensing or spraying, eg. inkjet type, piezo actuated ejection of droplets from capillaries
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• 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 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: G05D 7/0629 characterised by the type of regulator means
• CPC Class Codes: Y10T 137/0318 Processes
• CPC Class Codes: Y10T 137/206 Flow affected by fluid contact, energy field or coanda effect [e.g., pure fluid device or system]

Abstract

Droplet actuators that include molecular barrier coatings are provided. The molecular barrier coating may be provided atop the conductive layer of the top substrate, atop the droplet operations electrodes of the bottom substrate, or both. Where the conductive layer of the top substrate and/or the droplet operations electrodes of the bottom substrate are formed of an electrically conductive organic polymer, such as poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), the molecular barrier coating helps to immobilize the contents of the PEDOT:PSS layer. Further, the molecular barrier coating reduces, preferably entirely eliminates, moisture from seeping into the electrically conducting organic polymer. Methods of conducting droplet operations using the disclosed droplet actuators are also provided.

Claims

1. A droplet actuator comprising:

a. a bottom substrate comprising droplet operations electrodes;

b. a top substrate separated from the bottom substrate to form a gap, the top substrate comprising a conductive layer;

c. a molecular barrier layer atop the conductive layer of the top substrate, and/or a molecular barrier layer atop the droplet operations electrodes of the bottom substrate; and

d. a hydrophobic layer atop the molecular barrier layer atop the conductive layer of the top substrate and/or atop the molecular barrier layer atop the droplet operations electrodes of the bottom substrate.

2. The droplet actuator of claim 1, further comprising a hydrophobic layer atop the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate.

3. The droplet actuator of claim 1, wherein the conductive layer of the top substrate and/or the droplet operations electrodes of the bottom substrate are formed of an electrically conductive organic polymer.

4. The droplet actuator of claim 3, wherein the electrically conductive organic polymer is poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:

PSS).

5. The droplet actuator of claim 4, wherein the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate immobilizes the contents of the conductive layer of the top substrate and/or the contents of the droplet operations electrodes of the bottom substrate.

6. The droplet actuator of claim 1, wherein the thickness of the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate is from about 1 nm to about 100.mu.m.

7. The droplet actuator of claim 1, wherein the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate is a molecular barrier coating.

8. The droplet actuator of claim 7, wherein the molecular barrier coating comprises a stretchable gel.

9. The droplet actuator of claim 8, wherein the stretchable gel is selected from the group consisting of silicones, hydrogels, and polyethylene glycol derivatives.

10. The droplet actuator of claim 4, wherein the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate is a moisture barrier.

11. The droplet actuator of claim 4, wherein the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate is a sieve that allows water to pass therethrough while molecules larger than water molecules are blocked from passing through the molecular barrier layer.

12. The droplet actuator of claim 1, comprising a molecular barrier layer only atop the droplet operations electrodes of the bottom substrate, and wherein the conductive layer of the top substrate is formed of an electrically conductive material.

13. The droplet actuator of claim 12, wherein the conductive layer of the top substrate is formed of indium tin oxide.

14. The droplet actuator of claim 1, wherein there is not a molecular barrier layer atop the droplet operations electrodes of the bottom substrate, and wherein the droplet operations electrodes of the bottom substrate are formed of an electrically conductive material.

15. The droplet actuator of claim 14, wherein the droplet operations electrodes of the bottom substrate are formed of copper, aluminum, gold, or silver.

16. The droplet actuator of claim 1, wherein the droplet operations electrodes are on a side of bottom substrate that is facing droplet operations gap.

17. The droplet actuator of claim 1, wherein the conductive layer of the top substrate comprises a ground or reference electrode with respect to droplet operations electrodes of the bottom substrate.

18. A method of performing droplet operations on one or more droplets in a droplet actuator, comprising:

a. providing the droplet actuator of claim 10;

b. filling the droplet operations gap of the droplet actuator with a filler fluid;

c. transporting the one or more droplets in the droplet operations gap via droplet operations along the droplet operations electrodes and through the filler fluid;

wherein the one or more droplets are aqueous or are emulsions that include aqueous components and the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate is a moisture barrier to water passing from the droplet operations gap to the droplet operations electrodes of the bottom substrate and/or to the conductive layer of the top substrate.

19. A method of performing droplet operations on one or more droplets in a droplet actuator, comprising:

a. providing the droplet actuator of claim 11;

b. filling the droplet operations gap of the droplet actuator with a filler fluid;

c. transporting the one or more droplets in the droplet operations gap via droplet operations along the droplet operations electrodes and through the filler fluid; and

d. performing high-temperature electrowetting-on-dielectric (EWOD) methods on the one or more droplets, and wherein only water expelled from the PEDOT;

PSS pass through the molecular barrier layer atop the conductive layer of the top substrate and/or the molecular barrier layer atop the droplet operations electrodes of the bottom substrate while molecules larger than water molecules that can negatively affect the performance of the high-temperature EWOD methods are blocked from passing through the molecular barrier layer.

20. The method of claim 19, wherein the high-temperature EWOD methods comprise thermocycling in a polymerase chain reaction (PCR).