Methods for fabricating microfluidic structures

• US 6,719,868 B1
• Filed: 10/22/1999
• Issued: 04/13/2004
• Est. Priority Date: 03/23/1998
• Status: Expired due to Term

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: Schueller, Olivier J. A., Duffy, David C., Brittain, Scott T., Whitesides, George M., Rogers, John A.
• Primary Examiner(s): Aftergut, Jeff H.
• Assistant Examiner(s): Haran, John T.
• Application Number:
  US09/425,787
• Time in Patent Office: 1,635 Days
• Field of Search: 156/272.6, 156/273.3, 156/292, 156/306.3
• US Class Current: 156/272.6
• CPC Class Codes: B01L 2200/0689 Sealing
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2300/123 Flexible; Elastomeric
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• 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 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: G01N 21/45 using interferometric methods; using Schlieren methods
• CPC Class Codes: G01N 21/4788 Diffraction for sizing particles G01N15/0205
• CPC Class Codes: Y10T 428/24562 Interlaminar spaces
• CPC Class Codes: Y10T 428/2457 Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/24744 Longitudinal or transverse tubular cavity or cell
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

A system is provided for positioning separate portions of a sample in elongate, parallel channels of a sample chamber and to irradiate a sample in the chamber to create a diffraction pattern where the sample and chamber differ in refractive index. The system also can measure absorption of electromagnetic radiation by a sample in the chamber, and can measure the absorption simultaneously with measurement of diffraction by the sample.

Claims

1. A method comprising:

joining a pre-oxidized elastomeric surface to a second pre-oxidized surface, wherein the elastomeric surface and the second surface form an irreversible liquid-impermeable seal therebetween in a microfluidic structure.

2. A method as in claim 1, comprising joining the elastomeric surface and the second surface to form an irreversible liquid-impermeable seal therebetween in the absence of auxiliary adhesive.

3. A method as in claim 1, further comprising pre-oxidizing the elastomeric surface and the second surface by exposing the elastomeric surface and the second surface to plasma.

4. A method as in claim 1, wherein the joining step comprises joining first portions of the elastomeric surface to the second surface while leaving a second portion of the elastomeric surface, intervening the first portions of the elastomeric surface, free of contact with the second surface.

5. A method as in claim 1, the joining step comprising contacting first portions of the second surface with the elastomeric surface while leaving a second portion of the second surface, intervening the first portions of the second surface, free of contact with the elastomeric surface.

6. A method as in claim 1, wherein the second surface is polymeric.

7. A method as in claim 1, wherein the second surface is metal.

16. The method of claim 1, wherein the elastomeric surface comprises at least one microchannel.

17. The method of claim 1, comprising joining the elastomeric surface to the second pre-oxidized surface in the absence of auxiliary adhesive.

18. The method of claim 1, comprising joining the elastomeric surface to the second pre-oxidized surface at a temperature of between about 16°

C. and about 27°

C.

8. A method comprising:

applying an elastomeric surface to a second surface in the absence of auxiliary adhesive and at a temperature of between about 16°

C. and about 27°

C., wherein the elastomeric surface and the second surface bond to form an irreversible liquid-impermeable seal therebetween in a microfluidic structure.

9. A method as in claim 8, further comprising pre-oxidizing the elastomeric surface and the second surface prior to the applying step.

10. A method as in claim 8, further comprising exposing the elastomeric surface and the second surface to plasma prior to the applying step.

11. A method as in claim 8, wherein the second surface is polymeric.

12. A method as in claim 8, the applying step comprising contacting first portions of the elastomeric surface with the second surface while leaving a second portion of the elastomeric surface, intervening the first portions of the elastomeric surface, free of contact with the second surface.

13. A method as in claim 8, the applying step comprising contacting first portions on the second surface with the elastomeric surface while leaving a second portion of the second surface, intervening the first portions of the second surface, free of contact with the elastomeric surface.

14. A method as in claim 8, wherein the second surface is metal.

19. The method of claim 8, wherein the elastomeric surface comprises at least one microchannel.

20. The method of claim 8, wherein the temperature is between 18°

C. and about 23°

C.

15. A method comprising:

joining a pre-oxidized elastomeric surface, comprising at least one microchannel formed in the elastomeric surface, to a second pre-oxidized surface, wherein the elastomeric surface and the second surface form an irreversible liquid-impermeable seal therebetween.

21. The method of claim 15, comprising joining the elastomeric surface to the second pre-oxidized surface at a temperature of between about 16°

and about 27°

C.

22. The method of claim 15, wherein the temperature is between about 18°

C. and about 23°

C.

23. The method of claim 15, further comprising pre-oxidizing the elastomeric surface and the second surface by exposing the elastomeric surface and the second surface to plasma.

24. A method as in claim 15, wherein the joining step comprises joining first portions of the elastomeric surface to the second surface while leaving a second portion of the elastomeric surface, interventing the first portions of the elastomeric surface, free of contact with the second surface.

25. A method as in claim 15, the joining step comprising contact first portions of the second surface with the elastomeric surface while leaving a second portion of the second surface, interventing the first portions of the second surface, free of contact with the elastomeric surface.

26. A method as in claim 15, wherein the second surface is polymeric.

27. A method as in claim 15, wherein the second surface is metal.