Microfluidic structure and process for its manufacture

• US 5,376,252 A
• Filed: 11/10/1992
• Issued: 12/27/1994
• Est. Priority Date: 05/10/1990
• Status: Expired due to Term

• Current Assignee: Cellectricon AB
• Original Assignee: Pharmacia Biosensor AB (General Electric Company)
• Inventors: Ohman, Ove, Sjodin, Hakan, Jacobson, Gunilla, Ekstrom, Bjorn
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): STARSIAK, JOHN S
• Application Number:
  US07/946,332
• Time in Patent Office: 777 Days
• Field of Search: 210/198.2, 210/198.3, 210/658, 210/656, 73/61.53, 73/23.39, 204/299 R, 204/180.1
• US Class Current: 204/603
• CPC Class Codes: B01D 57/02 by electrophoresis treatment of water, waste water, sewage or sludge by electrophoresis C02F1/469; electrophoretic production of compounds or non-metals C25B7/00; investigating or analysing materials by using electrophoresis G01N27/26
• CPC Class Codes: B01L 2200/025 Align devices or objects to ensure defined positions relative to each other
• CPC Class Codes: B01L 2200/0689 Sealing
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0874 Three dimensional network
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0421 electrophoretic flow
• 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: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29C 35/08 by wave energy or particle radiation B29C64/00, B29C71/04 take precedence
• CPC Class Codes: B29C 45/00 Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor injection blow-moulding B29C49/06
• CPC Class Codes: B29D 24/002 formed with structures, e.g. cores placed between two plates or sheets, e.g. partially filled totally filled B29D99/0021
• CPC Class Codes: B29K 2105/24 crosslinked or vulcanised
• CPC Class Codes: B81C 1/00071 Channels
• CPC Class Codes: B81C 2201/019 Bonding or gluing multiple substrate layers
• CPC Class Codes: B81C 2201/034 Moulding
• CPC Class Codes: G01N 27/44704 Details; Accessories
• CPC Class Codes: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027
• CPC Class Codes: G01N 30/6052 body
• CPC Class Codes: G01N 30/6095 : Micromachined or nanomachined, e.g. micro- or nanosize

Abstract

The microfluidic structure comprises first and second substantially planar form-stable base layers and an intermediate spacing layer of elastic material, said spacing layer being recessed to define a microcavity or channel system with at least one of said first and second base layers. The structure is produced by moulding the spacing layer, optionally applied to or integral with a first base layer, against a planar mould, and the microcavity or channel system is completed by applying a second base layer, and optionally said first base layer, to the spacing layer.

Claims

1. A microfluidic structure, comprising:

first and second substantially planar form-stable base layers; and

a first intermediate spacing layer of elastic material, said first spacing layer being recessed to define a microcavity or channel system with at least one of said first and second base layers, said first spacing layer and at least one of said first and second base layers being made of the same material.

2. The structure of claim 1, wherein said first spacing layer is recessed through a thickness thereof such that side walls of the microcavity or channel system are formed by said first spacing layer and top and bottom walls are formed by said first and second base layers.

3. The structure of claim 1 or 2, wherein said first spacing layer is integral with one of said first and second base layers.

4. The structure of claim 3, wherein said first spacing layer fills part of a space between said first and second base layers and only forms wall members of the channel or microcavity defined by said structure.

5. The structure of claim 1, wherein at least one of said first and second base layers is flexible.

6. The structure of claim 1, wherein at least one of said first and second base layers is rigid.

7. The structure of claim 1, wherein said first spacing layer fills part of a space between said first and second base layers and only forms wall members of the channel or microcavity defined by said structure.

8. The structure of claim 1, wherein said structure is a plate for capillary electrophoresis.

9. The structure of claim 8, further comprising detector means arranged on one side of said first and second base layers.

10. The structure of claim 1, further comprising a second spacing layer, separated by said first and second base layers and a third base layer the channel or microcavity of said first spacing layer being connected to a channel or microcavity of said second spacing layer by a bore in an intermediate base layer.

11. The structure of claim 10, further comprising at least she additional spacing layer and base layer combination on top of said third base layer.

12. A process of producing a microfluidic structure, comprising the steps of:

(i) providing a planar mold surface having a relief pattern corresponding to a desired spacing layer geometry,

(ii) molding a spacing layer of elastic material against said planar mold surface, and

(iii) after removal from the mold, applying first and second substantially planar form-stable base layers to opposite sides of the spacing layer such that a channel or microcavity system is defined by the spacing layer with at least one of said first and second base layers.

13. The process of claim 12, further comprising the step of:

applying at least one additional spacing layer and base layer the produced structure.

16. The process of claim 12 or 14, wherein said relief pattern of the mold surface is produced by etching.

17. The process of claim 12 or 14, wherein said mold is made of single-crystalline silicon.

14. A process of producing a microfluidic structure comprising the steps of:

(a) providing a planar mold surface having a relief pattern corresponding to a desired spacing layer geometry,

(b) molding a spacing layer of elastic material against said planar mold surface, the spacing layer being attached to or integral with a first substantially planar form-stable base layer, and

(c) after removal from the mold, applying a second substantially planar form-stable base layer to the opposite side of the spacing layer, such that a channel or microcavity system is defined by the spacing layer with at least one of said first and second base layers.

15. The process of claim 14, further comprising the step of:

(d) molding at least two base layer supported spacing layers, stacked on top of each other, and applying said second base layer.

18. A process of producing a microfluidic structure comprising the steps of:

a) providing a planar mold having a relief pattern corresponding to a desired spacing layer geometry;

b) applying a first base layer against the planar mold;

c) injecting a cross-linkable polymer liquid or thermoplastic polymer melt into a cavity defined between a surface of the planar mold and the base layer (2);

d) stabilizing said injected polymer by cross-linking or temperature reduction;

e) removing the base layer and spacing layer from the planar mold; and

f) applying a second base layer to the spacing layer of said structure.

19. The process of claim 18, further comprising the step of:

(a) molding at least two base layer supported spacing layers, stacked on top of each other, and applying said second base layer.

20. The process of claim 19, wherein said cross-linking is effected by photo-initiation.

21. The process according of claim 19, wherein said relief pattern of the mold surface is produced by etching.

22. The process claim 19, wherein said mold is made of single-crystalline silicon.

23. A process of producing a microfluidic structure comprising the steps of:

a) providing a planar mold having a relief pattern corresponding to a desired spacing layer geometry;

b) applying a cross-linkable or thermoplastic spacing layer material, against the planar mold and pressing the spacing layer and the planar mold together;

c) stabilizing the spacing layer formed by cross-linking or temperature reduction;

d) removing the spacing layer from the mold; and

e) applying first and second base layers to opposite sides of the spacing layer.

24. The process of claim 23, further comprising the step of:

(f) applying at least one additional spacing layer and base layer to the produced structure.

27. The process of claim 23 or 25, wherein said cross-linking is effected by photo-initiation.

28. The process of claim 23 or 25, wherein said relief pattern of the mold surface is produced by etching.

29. The process of claim 23 or 25, wherein said mold is made of single-crystalline silicon.

30. The process of claim 23 or 25, wherein in step (b), the spacing layer and the planar mold are heated.

25. A process of producing a microfluidic structure comprising the steps:

a) providing a planar mold having a relief pattern corresponding to a desired spacing layer geometry;

b) applying a cross-linkable or thermoplastic spacing layer material supported by or integral with a first base layer against the planar mold and pressing the spacing layer and the planar mold together;

c) stabilizing the spacing layer formed by cross-linking or temperature reduction;

d) removing the spacing layer and the first base layer from the mold; and

e) applying a second base layer to the spacing layer.

26. The process of claim 25, further comprising the step of:

(f) producing at least two base layer supported spacing layers, stacked on top of each other, and applying said second base layer.