Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

• US 20050098435A1
• Filed: 09/23/2003
• Published: 05/12/2005
• Est. Priority Date: 02/04/1998
• Status: Active Grant

• Current Assignee: Ramsey J. Michael, Stephen C. Jacobson
• Original Assignee: Ramsey J. Michael, Stephen C. Jacobson
• Inventors: Ramsey, J. Michael, Jacobson, Stephen C.
• Granted Patent: US 7,297,243 B2
• Time in Patent Office: Days
• US Class Current: 204/518
• 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: B01D 61/422 Electrodialysis
• CPC Class Codes: B01D 61/427 Electro-osmosis
• CPC Class Codes: B01D 61/445 with bipolar membranes; Water splitting
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• CPC Class Codes: B01L 2400/049 vacuum
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: G01N 27/44704 Details; Accessories
• CPC Class Codes: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027

Abstract

A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. A method of controllably moving material comprising the steps of:

providing a microchannel device that includes a substrate having first, second, and third channels disposed therein, the first, second, and third channels communicating at a channel intersection, said second channel containing a membranous material that is characterized by an ability to conduct electrical current while inhibiting bulk material flow therethrough; and

providing a flow of a first material from said first channel into said third channel by applying a first electrical potential to said first channel and a second electrical potential to said second channel through said membranous material.

9. A method as set forth in claim 8 wherein the membranous material is a polymeric gel.

10. A method as set forth in claim 8 wherein the membranous material is a polyacrylamide gel.

36. A method as set forth in claim 8 comprising the step of providing the membranous material as porous glass.

37. A method as set forth in claim 8 comprising the step of providing the membranous material as a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

38. A method as set forth in claim 8 comprising the step of reversing the first and second electrical potentials to provide flow of the first material from the third channel into the first channel.

11. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. A method for pumping a material through a channel comprising the steps of:

providing a microchannel device that includes a substrate having first and second channels disposed therein, said first and second channels being in fluid communication at a channel intersection and containing a first fluidic material;

providing a membranous material in the first channel; and

inducing a hydraulic pressure in the second channel by applying an electrical potential between the first and second channels.

20. A method for pumping a material through a channel comprising the steps of:

providing a microchannel device that includes a substrate having first and second channels disposed therein said first and second channels being in fluid communication at a channel intersection and containing a first fluidic material;

providing a membranous material in the first channel;

providing a third channel that is in fluid communication with the first and second channels at the channel intersection;

providing a second membranous material in the third channel; and

inducing a hydraulic pressure in the second channel by applying an electrical potential between the first and third channels.

39. A method as set forth in claim 20 comprising the step of providing electroosmotic flow in the first membranous material that is greater than electroosmotic flow in the second membranous material.

21. (canceled)

22. (canceled)

23. (canceled)

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)

28. A device for the manipulation of liquid phase materials, comprising:

a substrate;

first and second channels formed on said substrate;

a reservoir in fluid communication with said first and second channels; and

a source of electrical potential operatively connected between said first and second channels for inducing electrokinetic transport of a fluid material from said reservoir into said second channel.

29. A device as set forth in claim 28 wherein said first channel contains a membranous material, said membranous material being characterized by an ability to conduct electrical current while inhibiting bulk material flow therethrough.

30. A device for the manipulation of liquid phase materials, comprising:

a substrate;

first, second and third channels formed on said substrate, said first, second, and third channels being in fluidic communication at a channel junction;

a membranous material disposed in said second channel, said membranous material being characterized by an ability to conduct electrical current while inhibiting bulk material flow therethrough; and

a source of electrical potential adapted to be selectively connected to said first and second channels for inducing transport of a material in said first and third channels.

31. A device as set forth in claim 30 wherein the substrate is formed of a gas-permeable material.

32. A device as set forth in claim 31 further comprising a nonporous coverplate, formed of an electrically insulating material and affixed to said substrate and a metallic electrode formed on said nonporous plate adjacent to said first channel, whereby electrical conduction can occur between said electrode and said second channel.

40. A device as set forth in claim 30 wherein the membranous material comprises a polymeric material or a porous glass material.

41. A device as set forth in claim 30 wherein the membranous material comprises a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

33. (canceled)

34. (canceled)

35. (canceled)

42. A method for minimizing electrochemically generated species in a sample material comprising the steps of:

providing a microchannel device that includes a substrate having first and second channels disposed therein;

providing a reservoir in fluid communication with said first and second channels; and

inducing electrokinetic transport of a fluid material from the reservoir into the second channel by applying an electrical potential across the first and second channels.

43. A method as set forth in claim 42 comprising the step of providing a membranous material in the first channel, said membranous material being characterized by an ability to conduct ionic current while inhibiting bulk transport therethrough.

44. A method as set forth in claim 43 comprising the step of providing the membranous material as a polymeric material or a porous glass material.

45. A method as set forth in claim 43 comprising the step of providing the membranous material as a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

46. A device for pumping a material through a channel comprising:

a substrate;

first and second channels formed on said substrate;

said first and second channels being in fluid communication at a first channel intersection;

a first membranous material disposed in the first channel; and

a source of electrical potential operatively connected to the first and second channels for inducing transport of a material in the second channel.

47. A device as set forth in claim 46 wherein the first membranous material comprises a polymeric material or a porous glass material.

48. A device as set forth in claim 46 wherein the first membranous material comprises a channel having a transverse dimension commensurate with the electrical double layer.

49. A device for the manipulation of liquid phase materials comprising:

a substrate;

first, second, and third channels formed on said substrate;

said first, second, and third channels being in fluid communication at a channel intersection;

a first membranous material disposed in the first channel and a second membranous material disposed in the second channel; and

a source of electrical potential operatively connected to the first and second channels for inducing transport of a material in the third channel.

50. A device as set forth in claim 49 wherein the first and second membranous materials are selected such that electroosmotic flow in the first membranous material is greater than electroosmotic flow in the second membranous material.

51. A device as set forth in claim 49 wherein the first membranous material comprises a polymeric material or a porous glass material.

52. A device as set forth in claim 49 wherein the first membranous material comprises a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

53. A device as set forth in claim 49 wherein the second membranous material comprises a polymeric material or a porous glass material.

54. A device as set forth in claim 49 wherein the second membranous material comprises a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

55. A method for pumping a material through a channel comprising the steps of:

providing a microchannel device that includes a substrate having first, second, and third channels disposed therein, said first and third channels being in fluid communication at a first channel intersection, said second and third channels being in fluid communication at a second channel intersection, and containing a first fluidic material;

providing a first membranous material in the first channel and a second membranous material in the second channel; and

inducing a hydraulic pressure in the third channel by applying an electrical potential between the first and second channels.

56. A method as set forth in claim 55 comprising the step of providing a third membranous material in the third channel.

57. A method as set forth in claim 56 comprising the step of providing electroosmotic flow in the third membranous material that is greater than electroosmotic flow in the first membranous material.

58. A method as set forth in claim 55 comprising the step of providing electroosmotic flow in the first membranous material that is greater than electroosmotic flow in the second membranous material.

59. A method as set forth in claim 55 wherein the step of providing the first membranous material comprises providing a polymeric material or a porous glass material as the first membranous material.

60. A method as set forth in claim 55 wherein the step of providing the first membranous material comprises forming at least one channel in the first channel that has a transverse dimension that is similar to the thickness of the electrical double layer.

61. A method as set forth in claim 55 wherein step of providing the second membranous material comprises providing a polymeric material or a porous glass material as the second membranous material.

62. A method as set forth in claim 55 wherein the step of providing the second membranous material comprises forming a channel in the second channel that has a transverse dimension that is similar to the thickness of the electrical double layer.

63. A method as set forth in claim 56 wherein the step of providing the third membranous material comprises providing a polymeric material or a porous glass material as the third membranous material.

64. A method as set forth in claim 56 wherein the step of providing the third membranous material comprises forming a channel in the third channel that has a transverse dimension that is similar to the thickness of the electrical double layer.

65. A device for the manipulation of liquid phase materials comprising:

a substrate;

first, second, and third channels formed on said substrate;

said first and third channels being in fluid communication at a first channel intersection;

said second and third channels being in fluid communication at a second channel intersection;

a first membranous material disposed in the first channel and a second membranous material disposed in the second channel; and

a source of electrical potential operatively connected to the first and second channels for inducing transport of a material in the third channel.

66. A device as set forth in claim 65 wherein a third membranous material is disposed in the third channel.

67. A device as set forth in claim 66 wherein the first and third membranous materials are selected to provide electroosmotic flow in the third membranous material that is greater than electroosmotic flow in the first membranous material.

68. A device as set forth in claim 66 wherein the first and second membranous materials are selected to provide electroosmotic flow in the first membranous material that is greater than electroosmotic flow in the second membranous material.

69. A device as set forth in claim 65 wherein the first membranous material comprises a polymeric material or a porous glass material.

70. A device as set forth in claim 65 wherein the first membranous material comprises a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

71. A device as set forth in claim 65 wherein the second membranous material comprises a polymeric material or a porous glass material.

72. A device as set forth in claim 65 wherein the second membranous material comprises a channel having a transverse dimension that is similar to the thickness of the electrical double layer.

73. A device as set forth in claim 66 wherein the third membranous material comprises a polymeric material or a porous glass material.

74. A device as set forth in claim 66 wherein the third membranous material comprises a channel having a transverse dimension that is similar to the thickness of the electrical double layer.