Single-sided light-actuated microfluidic device with integrated mesh ground

Patent metadata

Field	Value
Publication number	US-10569271-B2
Application number	US-201715785727-A
Country	US
Kind code	B2
Filing date	Oct 17, 2017
Priority date	Dec 5, 2014
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

Single-sided optoelectrowetting (SSOEW)-configured substrates are provided, as well as microfluidic devices that include such substrates. The substrates can include a planar electrode, a photoconductive (or photosensitive) layer, a dielectric layer (single-layer or composite), a mesh electrode, and a hydrophobic coating. Fluid droplets can be moved across the hydrophobic coating of such substrates in a light-actuated manner, upon the application of a suitable AC voltage potential across the substrate and the focusing of light into the photoconductive layer of the substrate in a location proximal to the droplets. Walls can be disposed upon the substrates to form the microfluidic devices. Together the walls and substrate can form a microfluidic circuit, through which droplets can be moved.

First claim

What is claimed:

1. A process for manipulating a droplet in a microfluidic device, the process comprising:
filling some or all of a microfluidic circuit of a microfluidic device with a first liquid medium;
said microfluidic device comprising:
(a) a base comprising:
a planar electrode;
a photoconductive layer;
a dielectric layer comprising at least a first layer of dielectric material;
a mesh ground electrode; and
a hydrophobic coating;
wherein the photoconductive layer is interposed between the planar electrode and the dielectric layer, with a bottom surface of the photoconductive layer adjoining a top surface of the planar electrode and a top surface of the photoconductive layer adjoining a bottom surface of the dielectric layer;
wherein the mesh ground electrode adjoins the dielectric layer, and wherein at least the first layer of dielectric material is interposed between the mesh ground electrode and the photoconductive layer;
wherein the planar electrode and the mesh ground electrode are configured to be connected to an AC voltage source; and
wherein, when the planar electrode and the mesh ground electrode are connected to opposing terminals of the AC voltage source, the base is capable of applying an opto-electrowetting (OEW) force to aqueous droplets in contact with the hydrophobic coating; and

(b) walls disposed on a top surface of said base;
(c) wherein the base and the walls together define the microfluidic circuit;

applying an AC voltage potential between said planar electrode and said mesh ground electrode of said base of said microfluidic device;
introducing a first droplet of liquid into the microfluidic circuit, wherein the first droplet is immiscible in the first liquid medium; and
moving the first droplet to a desired location within the microfluidic circuit by applying an electrowetting force to the first droplet.

2. The process of claim 1 , wherein said microfluidic device further comprises a cover, wherein the cover is disposed on the walls.

3. The process of claim 1 , wherein the first liquid medium is an oil.

4. The process of claim 1 , wherein the first liquid medium is a silicone oil, a fluorinated oil, or a combination of a silicone oil and a fluorinated oil.

5. The process of claim 1 , wherein the applied AC voltage potential is about 10 ppV to about 80 ppV.

6. The process of claim 1 , wherein the applied AC voltage potential is about 30 ppV to about 50 ppV.

7. The process of claim 1 , wherein the applied AC voltage potential has a frequency of about 1 to 100 kHz.

8. The process of claim 1 , wherein the applied AC voltage potential has a frequency of about 5 to 20 kHz.

9. The process of claim 1 , wherein the microfluidic device further comprises a droplet generator, and wherein the droplet generator introduces the first droplet into the microfluidic circuit.

10. The process of claim 1 , wherein the first droplet comprises an aqueous solution.

11. The process of claim 10 , wherein the aqueous solution is a cell culture medium.

12. The process of claim 1 , wherein the first droplet comprises at least one micro-object.

13. The process of claim 12 , wherein the at least one micro-object is a biological micro-object, a capture bead having an affinity for a material of interest, or a combination of a biological micro-object and a capture object.

14. The process of claim 13 , wherein the biological micro-object is a cell.

15. The process of claim 14 , wherein the material of interest is selected from the group consisting of a biological cell secretion, DNA, genomic DNA, mitochondrial DNA, RNA, mRNA, miRNA, and any combination thereof.

16. The process of claim 1 , wherein the first droplet comprises a reagent.

17. The process of claim 16 , wherein the reagent is a cell lysis reagent, a non-ionic detergent, a proteolytic enzyme, or any combination thereof.

18. The process of claim 1 , further comprising:
introducing a second droplet of liquid into the microfluidic circuit, wherein the liquid of the second droplet is immiscible in the first liquid medium but miscible with the liquid of the first droplet;
moving the second droplet to a location within the microfluidic circuit adjacent to the first droplet by applying an electrowetting force to the second droplet; and
merging the second droplet with the first droplet to form a combined droplet.

19. The process of claim 18 , wherein the second droplet is merged with the first droplet by applying an electrowetting force to the second and/or the first droplet.

20. The process of claim 18 , wherein the first droplet comprises a biological cell and the second droplet comprises a reagent.

21. The process of claim 20 , wherein the reagent contained in the second droplet is a lysis buffer, a fluorescent label, or a luminescent assay reagent.

22. The process of claim 20 , wherein the reagent contained in the second droplet is a lysis buffer, and wherein said biological cell is lysed upon merger of the first droplet and the second droplet.

23. The process of claim 18 , wherein applying an electrowetting force to move and/or merge droplets comprises changing an effective electrowetting characteristic of a region of the top surface of the base of the microfluidic device proximal to the droplet(s).

24. The process of claim 23 , wherein changing an effective electrowetting characteristic comprises activating electrowetting electrodes in a photoconductive layer of the base of the microfluidic device proximal to the droplet(s).

25. The process of claim 24 , wherein activating the electrowetting electrodes in the photoconductive layer of the base of the microfluidic device proximal to the droplet(s) comprises directing a pattern of light into the photoconductive layer of the base of the microfluidic device proximal to the droplet(s).

Assignees

• Univ California
• Berkeley Lights Inc

Inventors

• Wu Ming-Chiang
• Loo Jodi Tsu-An
• Pei Shao Ning
• Mathieu Gaetan L
• Gong Jian
• Lowe Jr Randall D
• Valley Justin K

Classifications

• B01L3/502792

  for moving individual droplets on a plate, e.g. by locally altering surface tension · CPC title

• B01L2400/0427

  Electrowetting · CPC title

• B01L3/502707 Primary

  characterised by the manufacture of the container or its components · CPC title

• B01L2300/0816

  Cards, e.g. flat sample carriers usually with flow in two horizontal directions · CPC title

• B01L2300/0858

  Side walls · CPC title