Structures for controlling light interaction with microfluidic devices

• US 8,221,700 B2
• Filed: 02/02/2010
• Issued: 07/17/2012
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Opko Diagnostics, LLC (Opko Health, Inc.)
• Original Assignee: Opko Diagnostics, LLC (Opko Health, Inc.)
• Inventors: Steinmiller, David, Linder, Vincent
• Primary Examiner(s): Sines, Brian J
• Application Number:
  US12/698,451
• Publication Number:
  US 20100196207A1
• Time in Patent Office: 896 Days
• Field of Search: 422/50, 422/68.1, 422/81, 422/82.05, 422/82.07, 422/82.08, 422/82.09, 422/82.11, 422/502, 422/503, 436/43, 436/164, 436/172
• US Class Current: 422/503
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/04 Closures and closing means
• CPC Class Codes: B01L 2300/0627 Sensor or part of a sensor is integrated
• 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 2300/12 Specific details about materials
• 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: C12Y 304/21077 Semenogelase (3.4.21.77), i.e. prostate specific antigen or PSA or kallikrein 3
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence
• CPC Class Codes: G01N 2333/96455 Kallikrein (3.4.21.34; 3.4.21.35)
• CPC Class Codes: G01N 33/53 Immunoassay; Biospecific binding assay; Materials therefor
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G01N 33/545 Synthetic resin
• CPC Class Codes: G01N 33/57488 involving compounds identifable in body fluids
• CPC Class Codes: Y10T 436/11 Automated chemical analysis

Abstract

Systems and methods for improved measurement of absorbance/transmission through fluidic systems are described. Specifically, in one set of embodiments, optical elements are fabricated on one side of a transparent fluidic device opposite a series of fluidic channels. The optical elements may guide incident light passing through the device such that most of the light is dispersed away from specific areas of the device, such as intervening portions between the fluidic channels. By decreasing the amount of light incident upon these intervening portions, the amount of noise in the detection signal can be decreased when using certain optical detection systems. In some embodiments, the optical elements comprise triangular grooves formed on or in a surface of the device. The draft angle of the triangular grooves may be chosen such that incident light normal to the surface of the device is redirected at an angle dependent upon the indices of refraction of the external medium (e.g., air) and the device material. Advantageously, certain optical elements described herein may be fabricated along with the fluidic channels of the device in one step, thereby reducing the costs of fabrication. Furthermore, in some cases the optical elements do not require alignment with a detector and, therefore, facilitate assembly and/or use by an end user.

Claims

1. A fluidic device comprising:

an article including first and second opposing sides;

first and second adjacent microfluidic channel segments, each integral to the first side of the article;

an intervening portion positioned substantially between the first and second adjacent microfluidic channel segments; and

a first optical element integral to the second side of the article and positioned substantially between the first and second adjacent microfluidic channel segments and opposite the intervening portion,

wherein the first optical element is adapted and arranged such that when a portion of the article is exposed to light at a first intensity, the first optical element redirects at least a portion of the light away from the intervening portion, such that the intervening portion is not exposed to the light or is exposed to the light at a second intensity lower than an intensity of the light at the intervening portion absent the first optical element.

3. A fluidic device as in claim 1, comprising a plurality of microfluidic channel segments, wherein the first optical element is adapted and arranged such that when the second side of the article is exposed to light at the first intensity at an angle of incidence between 80°

to 95°

, the intervening portion is not exposed to light or is exposed to the light at a second intensity lower than the intensity of the light at the intervening portion absent the first optical element.

4. A fluidic device as in claim 1, comprising a plurality of optical elements.

5. A fluidic device as in claim 1, comprising a plurality of intervening portions.

6. A fluidic device as in claim 1, wherein the first optical element is substantially triangular.

7. A fluidic device as in claim 1, wherein the first optical element is concave.

8. A fluidic device as in claim 1, wherein the first optical element is convex.

9. A fluidic device as in claim 1, wherein no line drawn between any first point on or within the first microfluidic channel segment and any second point on or within the second microfluidic channel segment intersects any point on or within the first optical element.

10. A fluidic device as in claim 1, further comprising a second optical element, wherein no line drawn between any first point on or within the first optical element and any second point on or within the second optical element intersects any point on or within the first or second microfluidic channel segments.

11. A fluidic device as in claim 1, wherein the first side is a first surface of the article.

12. A fluidic device as in claim 11, wherein the second side is a second surface of the article.

13. A fluidic device as in claim 1, wherein the first optical element comprises a cross-sectional dimension of at least about 50 microns.

14. A fluidic device as in claim 1, wherein redirecting light comprises refracting light.

15. A fluidic device as in claim 1, wherein redirecting light comprises reflecting light.

16. A fluidic device as in claim 1, wherein the first optical element comprises a substantially opaque material.

17. A fluidic device as in claim 1, wherein the first optical element comprises a reflective surface.

18. A fluidic device as in claim 1, wherein the first optical element comprises an open channel.

19. A fluidic device as in claim 1, wherein the first optical element comprises a substantially enclosed channel.

20. A fluidic device as in claim 1, wherein the first optical element comprises a fluid.

21. A fluidic device as in claim 20, wherein the fluid comprises a dye.

22. A fluidic device as in claim 1, wherein the first optical element has a draft angle between about 12°

and about 60°

.

23. A fluidic device as in claim 1, wherein the first optical element has a draft angle between about 30°

and about 40°

.

24. A fluidic device as in claim 1, wherein the first microfluidic channel segment is part of a serpentine channel.

25. A fluidic device as in claim 1, wherein the article is a single, integral piece of material without joined layers.

26. A fluidic device as in claim 1, wherein the article is formed of a polymeric material.

27. A fluidic device as in claim 26, wherein the polymeric material is selected from polystyrene, cyclo-olefin-copolymer, polymethylmethacrylate, and polycarbonate.

28. A fluidic device as in claim 1, wherein the article is made by injection molding.

29. A fluidic device as in claim 1, wherein the first optical element directs at least 50% of the incident light away from the intervening portion.

30. A fluidic device as in claim 1, wherein the first optical element has a longest width greater than or equal to the width of the intervening portion positioned substantially between the first microfluidic channel segment and the second microfluidic channel segment, but less than the combination of the widths of the two microfluidic channel segments and the width of the intervening portion.

31. A fluidic device as in claim 1, further comprising a cover positioned over one or more microfluidic channel segments to substantially enclose the one or more microfluidic channel segments, wherein the cover comprises a tape.

32. A fluidic device as in claim 1, further comprising a reaction site in fluid communication with the first microfluidic channel segment.

33. A fluidic device as in claim 32, wherein the reaction site comprises a binding partner associated with a surface of the first microfluidic channel segment.

34. A fluidic device as in claim 33, wherein the binding partner comprises an antibody or an antigen.

35. A fluidic device as in claim 1, further comprising a detector associated with one or more microfluidic channel segments, wherein the detector is adapted and arranged to determine light transmission through the one or more microfluidic channel segments.

36. A fluidic device as in claim 1, wherein the first optical element is adapted and arranged such that when a portion of the article is exposed to light at a first intensity, the first optical element redirects at least a portion of the light away from the intervening portion, such that the intervening portion is exposed to the light at a second intensity at least 25% lower than an intensity of the light at the intervening portion absent the first optical element.

37. A fluidic device as in claim 1, wherein the first optical element is adapted and arranged such that when a portion of the article is exposed to light at a first intensity, the first optical element redirects at least a portion of the light away from the intervening portion, such that the intervening portion is exposed to the light at a second intensity at least 75% lower than an intensity of the light at the intervening portion absent the first optical element.

38. A fluidic device as in claim 3, wherein the second intensity is at least 50% lower than the first intensity.

39. A fluidic device as in claim 1, wherein the intervening portion is a portion of the first surface of the article.

40. A fluidic device as in claim 1, wherein at least one optical element is adapted and arranged such that when a portion of the article is exposed to light, the at least one optical element redirects at least a portion of the light away from a surface portion of the first side, the surface portion being adjacent to at least one microfluidic channel segment.

41. A fluidic device as in claim 1, wherein the first optical element is adapted and arranged such that when a portion of the article is exposed to light at a first intensity, the first optical element redirects at least a portion of the light incident upon the first optical element in a direction away from a central plane of the first optical element such that the portion of the device directly below the first optical element is not exposed to the light or is exposed to the light at a second intensity at least 25% lower than the first intensity.

42. A fluidic device as in claim 1, wherein the first and/or second microfluidic channel segments are sections of a microfluidic channel comprising a meandering configuration including multiple turns, each turn of the meandering channel being a different channel segment.

43. A fluidic device as in claim 1, wherein the intervening portion is a non-channel portion.

44. A fluidic device as in claim 1, wherein the first and/or second microfluidic channel segments has a length of at least 1 cm.

2. A fluidic device comprising:

an article comprising first and second sides;

a first microfluidic channel segment integral to the first side of the article;

first and second adjacent optical elements, each integral to the second side of the article, wherein the first microfluidic channel segment is positioned substantially between the first and second adjacent optical elements;

a cover positioned over the first microfluidic channel segment so as to substantially enclose the first microfluidic channel segment; and

an intervening surface portion at the second side of the article positioned substantially between the first and second adjacent optical elements, the intervening surface portion being substantially parallel to a surface portion of the cover that substantially encloses the first microfluidic channel segment.

45. A fluidic device as in claim 2, comprising a second microfluidic channel segment and an intervening portion positioned substantially between the first and second microfluidic channel segments, wherein the first optical element is adapted and arranged such that when the second side of the article is exposed to light at the first intensity at an angle of incidence between 80°

to 95°

, the intervening portion positioned between the first and second microfluidic channel segments is not exposed to light or is exposed to the light at a second intensity lower than the intensity of the light at the intervening portion absent the first optical element.

46. A fluidic device as in claim 2, wherein the first optical element is substantially triangular.

47. A fluidic device as in claim 2, wherein the first optical element is concave.

48. A fluidic device as in claim 2, wherein the first optical element comprises a cross-sectional dimension of at least about 50 microns.

49. A fluidic device as in claim 2, wherein the first optical element comprises a substantially opaque material.

50. A fluidic device as in claim 2, wherein the first optical element comprises a reflective surface.

51. A fluidic device as in claim 2, wherein the first optical element comprises a fluid.

52. A fluidic device as in claim 2, wherein the first optical element has a draft angle between about 12°

and about 60°

.

53. A fluidic device as in claim 2, wherein the first microfluidic channel segment is part of a serpentine channel.

54. A fluidic device as in claim 2, wherein the article is a single, integral piece of material without joined layers.

55. A fluidic device as in claim 2, wherein the article comprises a second microfluidic channel segment, and wherein the first optical element has a longest width greater than or equal to the width of an intervening portion positioned substantially between the first microfluidic channel segment and the second microfluidic channel segment, but less than the combination of the widths of the two microfluidic channel segments and the width of the intervening portion.

56. A fluidic device as in claim 55, wherein the first optical element is adapted and arranged such that when a portion of the article is exposed to light at a first intensity, the first optical element redirects at least a portion of the light away from the intervening portion, such that the intervening portion is exposed to the light at a second intensity at least 25% lower than an intensity of the light at the intervening portion absent the first optical element.

57. A fluidic device as in claim 45, wherein the second intensity is at least 50% lower than the first intensity.

58. A fluidic device as in claim 2, wherein the article comprises a second microfluidic channel segment, and wherein the first and/or second microfluidic channel segments are sections of a microfluidic channel comprising a meandering configuration including multiple turns, each turn of the meandering channel being a different channel segment.

59. A fluidic device as in claim 58, wherein the first and/or second microfluidic channel segments has a length of at least 1 cm.