Fluidic impedances in microfluidic system

• US 6,561,208 B1
• Filed: 04/14/2000
• Issued: 05/13/2003
• Est. Priority Date: 04/14/2000
• Status: Expired due to Term

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Nanostream, Inc.
• Inventors: Dantsker, Eugene, Pezzuto, Marci, OʼConnor, Stephen D.
• Primary Examiner(s): CHAMBERS, A MICHAEL
• Application Number:
  US09/550,184
• Time in Patent Office: 1,124 Days
• Field of Search: 137/833, 137/15.18, 251/368
• US Class Current: 137/15.18
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2200/0621 Control of the sequence of chambers filled or emptied
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2300/0874 Three dimensional network
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: F15C 1/02 Details , e.g. special constructional devices for circuits with fluid elements, such as resistances, capacitive circuit elements; devices preventing reaction coupling in composite elements servomotor systems adapted for maintaining constant speed F15B11/05; Switch boards; Programme devices hydraulic programme control F15B21/02
• CPC Class Codes: F15D 1/02 in pipes or conduits
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0017 Capillary or surface tension valves, e.g. using electro-wetting or electro-capillarity effects
• CPC Class Codes: F16K 99/0028 Valves having multiple inlets or outlets
• CPC Class Codes: F16K 99/0049 using an electroactive polymer [EAP]
• CPC Class Codes: F16K 99/0055 actuated by fluids
• CPC Class Codes: F16K 99/0057 the fluid being the circulating fluid itself, e.g. check valves
• CPC Class Codes: Y10T 137/0491 : Valve or valve element assembling, disassembling, or replacing
• CPC Class Codes: Y10T 137/2191 : By non-fluid energy field affecting input [e.g., transducer]
• CPC Class Codes: Y10T 137/2224 : Structure of body of device
• CPC Class Codes: Y10T 137/598 : With repair, tapping, assembly, or disassembly means
• CPC Class Codes: Y10T 137/8242 : Electrical
• CPC Class Codes: Y10T 137/86035 : Combined with fluid receiver

Abstract

The invention provides microfluidic devices with embedded fluidic impedances. Such impedances do not allow fluid to pass at a low differential pressure, but allow fluid to flow at a higher differential pressure. Impedances are formed by the three dimensional overlap of two or more channels contained within layers of the device. Such devices can be rapidly protyped and can be assembled to contain multiple fluidic impedances to perform complex fluid handling tasks, including metering defined volumes of samples and dividing samples into aliquots.

Claims

1. A microfluidic device comprising:

a first layer having at least one first channel therein, wherein said first channel has at least one dimension smaller than 500 microns;

a second layer having at least one second channel therein, wherein said second channel has a least one dimension smaller than 500 microns; and

wherein said first and second channels are in fluid communication at an overlap region which hinders fluid flow between said first channel and said second channel.

2. The device of claim 1 wherein said first layer and said second layer are substantially planar.

3. The microfluidic device of claim 1 further comprising a lower support layer.

4. The microfluidic device of claim 1 further comprising a top layer.

5. The microfluidic device of claim 1 wherein said overlap region has an overlap area of less than about 4 square millimeters.

6. The microfluidic device of claim 5 wherein said overlap region has an overlap area of less than about 1 square millimeter.

7. The microfluidic device of claim 6 wherein said overlap region has an overlap area of less than about 0.5 square millimeters.

8. The microfluidic device of claim 1 wherein said first layer and said second layer are integral.

9. The microfluidic device of claim 1 wherein said first layer and said second layer are held together with pressure.

10. The microfluidic device of claim 1 wherein said first layer and said second layer are adhered with an adhesive.

11. The microfluidic device of claim 10 wherein said adhesive is selected from the group consisting of rubber-based adhesives, acrylic-based adhesives, silicone-based and gum-based adhesives.

12. The microfluidic device of claim 1 wherein at least one of said first layer and said second layer is self-adhesive.

13. The microfluidic device of claim 1 wherein at least one of said first layer and said second layer comprises an adhesive tape.

14. The microfluidic device of claim 13 wherein the adhesive tape has adhesive on one side.

15. The microfluidic device of claim 13 wherein the adhesive tape has adhesive on both sides.

16. The microfluidic device of claim 13 wherein the adhesive tape is selected from the group consisting of pressure-sensitive tapes, temperature-sensitive tapes, chemically activated tapes and optically-activated tapes.

17. The microfluidic device of claim 1 wherein said first layer and said second layer comprise materials selected from the group consisting of polymers, papers, fabrics and foils.

18. The microfluidic device of claim 1 wherein said first layer and said second layer comprise polymers selected from the group consisting of polyesters, polyimides, vinyls, acrylics, polycarbonates, polytetrafluorethylenes, polyurethanes, polyethylenes, polypropylenes, polyvinylidene fluorides, nylons, polyethersulfones, ABS, polyphenylene oxides, silicones, and derivatives thereof.

19. The microfluidic device of claim 1 wherein said first layer and said second layer are adjacent.

20. The microfluidic device of claim 1 further comprising an at least one spacer layer separating said first and said second layers, wherein said spacing layer has an aperture positioned such that said first and said second channels can communicate through said aperture.

21. The microfluidic device of claim 1 further comprising a third layer having a third channel therein wherein said third channel communicates with at least one of said first and said second channels.

22. The microfluidic device of claim 21 wherein said third channel is in communication with said first and second channels at said overlap region.

23. The microfluidic device of claim 1 further comprising an outlet port in communication with one of said first and second channels.

24. The microfluidic device of claim 23 further wherein said outlet port has a semi-permeable membrane that selectively allows a gas to pass through said membrane while substantially hindering passage of a liquid.

25. The microfluidic device of claim 24 further comprising a third layer wherein said semi-permeable membrane forms all or part of said third layer.

26. The microfluidic device of claim 24 wherein said semi-permeable membrane is a polymeric material.

27. The microfluidic device of claim 25 wherein said polymeric material has pores in the range of between about 0.1 microns and about 100 microns.

28. The microfluidic device of claim 1 wherein said first and second channels have top, bottom and side surfaces.

29. The microfluidic device of claim 28 wherein any one of said surfaces is chemically treated.

30. The microfluidic device of claim 29 wherein said chemical treatment is selected from the group consisting of plasma cleaning and chemical etching.

31. The microfluidic device of claim 29 wherein said surface is chemically derivatized with a biomolecule selected from the group consisting of nucleic acids, proteins and carbohydrates.

32. The microfluidic device of claim 1, further comprising a filter material in fluid communication with the first channel or second channel.

33. A microfluidic device comprising:

a plurality of layers defining a first, a second, and a third channel, wherein each channel has at least one dimension smaller than 500 microns and at least two of the channels are defined in different layers;

wherein the first channel is in fluid communication with the second channel at a first overlap region that hinders flow between the first channel and the second channel; and

wherein the first channel is in fluid communication with the third channel at a second overlap region that hinders flow between the first channel and the third channel.

34. The microfluidic device of claims 33 wherein fluid introduced into the first channel overcomes the hindrance of the first overlap region and the hindrance of the second overlap region in a predictable sequence.

35. The microfluidic device of claim 33 wherein fluid introduced into the first channel overcomes the hindrance of the first overlap region at a first pressure to permit fluid to enter the second channel, and fluid introduced into the first channel overcomes the hindrance of the second overlap region at a second pressure to permit fluid to enter the third channel.

36. The microfluidic device of claim 35 wherein the second pressure is substantially greater than the first pressure.

37. The microfluidic device of claim 36 wherein the second pressure is at least about double the first pressure.

38. The microfluidic device of claim 33 wherein at least two of the first, second, and third layer are adjacent layers.

39. The microfluidic device of claim 33 wherein the layers are adhesively bonded.

40. The microfluidic device of claim 33 wherein at least one of the channels is defined in a stencil layer.

41. The microfluidic device of claim 33 wherein the first, second, and third layer comprise materials selected from the group consisting of polymers, papers, fabrics and foils.