Microfluidic devices and methods of manufacture thereof

• US 8,877,320 B2
• Filed: 02/17/2012
• Issued: 11/04/2014
• Est. Priority Date: 02/21/2011
• Status: Active Grant

• Current Assignee: STRATEC Consumables GmbH (Stratec SE)
• Original Assignee: Sony DADC Austria AG (Sony Group Corp.)
• Inventors: Naisby, Andrew John, Torello Arevalo, Miguel Angel, Kugler, Josef, Reiter, Wolfgang Franz
• Primary Examiner(s): Austin, Aaron
• Assistant Examiner(s): Pleszczynska, Joanna
• Application Number:
  US13/399,593
• Publication Number:
  US 20120213975A1
• Time in Patent Office: 991 Days
• Field of Search: 428/161, 428/164, 428/165, 428/172, 428/173, 428/459, 428/500, 428/474.4, 422/50, 422/129, 422/130, 422/131, 422/198, 422/199, 422/240, 422/603, 204/600, 204/601, 436/150, 436/180, 436/806, 427/123, 427/125, 427/214, 427/220, 427/404
• US Class Current: 428/161
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• 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: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027
• CPC Class Codes: H03L 7/23 with pulse counters or frequency dividers
• CPC Class Codes: Y10T 428/24521 with component conforming to contour of nonplanar surface
• CPC Class Codes: Y10T 428/24545 Containing metal or metal compound
• CPC Class Codes: Y10T 428/24554 including cellulosic or natural rubber component
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/2462 with partial filling of valleys on outer surface

Abstract

A microfluidic device comprising: a substrate having a microfluidic channel, an electrically conductive feature comprising an electrically conductive layer arranged on a primer layer and positioned with reference to the microfluidic channel, wherein the primer layer comprises: (i) an organic polymer selected from the group consisting of. (a) a homopolymer or copolymer including a vinyl lactam repeating unit, (b) a cellulose ether; (c) polyvinyl alcohol; and (d) unmodified or modified gelatin; and (ii) a porous particulate material, the organic polymer being dispersed in the porous particulate material, is provided. Methods for manufacturing the microfluidic devices and their use in a number of applications are also provided.

Claims

1. A microfluidic device, comprising:

a substrate comprising a microfluidic channel; and

an electrically conductive feature comprising an electrically conductive layer arranged on a primer layer and positioned with reference to the microfluidic channel, wherein the primer layer comprises;

(i) an organic polymer selected from the group consisting of

(a) a homopolymer or copolymer comprising a vinyl lactam repeating unit,

(b) a cellulose ether,

(c) polyvinyl alcohol, and

(d) unmodified or modified gelatin, and

(ii) a porous particulate material,

wherein the porous particulate material is dispersed in the organic polymer, and

wherein the microfluidic channel comprises a side wall portion that joins an upper surface of the substrate at a rim and a lateral separation δ

exists between the rim of the microfluidic channel and the edge of the electrically conductive layer.

2. The microfluidic device of claim 1, wherein the primer layer comprises at least 70% by weight of the porous particulate material, based on a total weight of the organic polymer and porous particulate material.

3. The microfluidic device of claim 2, wherein the primer layer comprises up to 30% by weight of the organic polymer, based on a total weight of the organic polymer and porous particulate material.

4. The microfluidic device of claim 1, wherein the primer layer comprises at least 90% by weight of the porous particulate material, based on a total weight of the organic polymer and porous particulate material.

5. The microfluidic device of claim 4, wherein the primer layer comprises up to 10% by weight of the organic polymer, based on a total weight of the organic polymer and porous particulate material.

6. A method of manufacturing a microfluidic device, the method comprising:

(A) applying a primer layer to a substrate comprising a microfluidic channel, the primer layer comprising;

(i) an organic polymer selected from the group consisting of

(a) a homopolymer or copolymer comprising a vinyl lactam repeating unit,

(b) a cellulose ether,

(c) polyvinyl alcohol, and

(d) unmodified or modified gelatin, and

(ii) a porous particulate material, wherein the porous particulate material is dispersed in the organic polymer;

(B) applying a conductive ink layer over the primer layer at a position referenced to the microfluidic channel, the conductive ink comprising electrically conductive particles dispersed in a humectant organic solvent,

wherein during (A) applying the primer layer and/or (B) applying the conductive ink layer, the primer layer and/or the conductive ink layer are applied to the microfluidic channel, and

wherein the microfluidic channel comprises a side wall portion that joins an upper surface of the substrate at a rim and the conductive ink layer is applied in the microfluidic channel so that a lateral separation δ

exists between the rim of the conductive ink channel and the edge of the conductive ink layer.

7. The method according to claim 6, wherein, during (A) applying the primer layer and/or (B) applying the conductive ink layer, the primer layer and/or the conductive ink layer are applied in solution to the microfluidic channel and are distributed through the microfluidic channel by capillary action.

8. The method according to claim 6, wherein the organic polymer is a homopolymer or copolymer of vinyl pyrrolidone.

9. The method according to claim 8, wherein the organic polymer is a copolymer of vinyl pyrrolidone and dimethylaminoethylmethacrylate.

10. The method according to claim 6, wherein the porous particulate material is selected from the group consisting of silica, alumina, titania, a zeolite, and barium sulphate.

11. The method according to claim 6, wherein the primer layer is applied to the substrate diluted in a hydrophilic solvent.

12. The method according to claim 11, wherein the hydrophilic solvent is a glycol ether or a mixture thereof.

13. The method according to claim 6, wherein the electrically conductive particles in the conductive ink comprise a metal selected from the group consisting of nickel, copper, palladium, silver, platinum and gold, or any mixture thereof.

14. The method according to claim 6, wherein the humectant organic solvent in the conductive ink is a polyol.

15. A microfluidic device manufactured according to the method of claim 6.