Thermal microvalves

• US 8,617,905 B2
• Filed: 12/05/2011
• Issued: 12/31/2013
• Est. Priority Date: 09/15/1995
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Burns, Mark A., Johnson, Brian N., Chen, Michael
• Primary Examiner(s): LUDLOW, JAN M
• Application Number:
  US13/311,087
• Publication Number:
  US 20120077231A1
• Time in Patent Office: 757 Days
• Field of Search: 436/180, 422502-504, 422/537, 137/74
• US Class Current: 436/180
• CPC Class Codes: B01F 25/14 Mixing drops, droplets or bodies of liquid which flow together or contact each other micromixers using where the materials to be mixed are in the form of droplets B01F33/302
• CPC Class Codes: B01F 25/31 in conduits or tubes through which the main component flows
• CPC Class Codes: B01F 33/3021 the components to be mixed being combined in a single independent droplet, e.g. these droplets being divided by a non-miscible fluid or consisting of independent droplets
• CPC Class Codes: B01F 33/3022 the components being formed by independent droplets which are alternated, the mixing of the components being achieved by diffusion between droplets
• CPC Class Codes: B01F 33/30351 using hydrophilic/hydrophobic surfaces
• CPC Class Codes: B01F 33/3039 with mixing achieved by diffusion between layers
• CPC Class Codes: B01F 35/7172 using capillary forces
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 2219/00783 Laminate assemblies, i.e. the reactor comprising a stack of plates
• CPC Class Codes: B01J 2219/00822 Metal
• CPC Class Codes: B01J 2219/00828 Silicon wafers or plates
• CPC Class Codes: B01J 2219/00831 Glass
• CPC Class Codes: B01J 2219/00837 comprising coatings other than catalytically active coatings
• CPC Class Codes: B01J 2219/00853 Employing electrode arrangements
• CPC Class Codes: B01J 2219/0086 Dimensions of the flow channels
• CPC Class Codes: B01J 2219/00873 Heat exchange
• CPC Class Codes: B01J 2219/00889 Mixing
• CPC Class Codes: B01J 2219/00891 Feeding or evacuation
• CPC Class Codes: B01J 2219/00957 Compositions or concentrations
• CPC Class Codes: B01J 2219/00961 Temperature
• CPC Class Codes: B01J 2219/0097 : Optical sensors
• CPC Class Codes: B01L 2200/0605 : Metering of fluids
• CPC Class Codes: B01L 2300/0816 : Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/1827 : using resistive heater
• CPC Class Codes: B01L 2400/0442 : thermal energy, e.g. vaporisation, bubble jet
• CPC Class Codes: B01L 2400/0487 : fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0677 : phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• CPC Class Codes: B01L 2400/0688 : surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 2400/0694 : vents used to stop and induce flow, backpressure valves
• 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 3/502738 : characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502784 : specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: B01L 7/52 : with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: F15B 13/0807 : Manifolds
• CPC Class Codes: F15C 5/00 : Manufacture of fluid circuit elements; Manufacture of assemblages of such elements integrated circuits
• CPC Class Codes: F16K 2099/0071 : with latching means
• CPC Class Codes: F16K 2099/0074 : using photolithography, e.g. etching
• CPC Class Codes: F16K 2099/0076 : using electrical discharge machining [EDM], milling or drilling
• CPC Class Codes: F16K 2099/008 : Multi-layer fabrications
• CPC Class Codes: F16K 2099/0084 : Chemistry or biology, e.g. "lab-on-a-chip" technology
• 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 99/0015 : Diaphragm or membrane valves
• CPC Class Codes: F16K 99/0017 : Capillary or surface tension valves, e.g. using electro-wetting or electro-capillarity effects
• CPC Class Codes: F16K 99/0019 : Valves using a microdroplet or microbubble as the valve member
• CPC Class Codes: F16K 99/0034 : Operating means specially adapted for microvalves
• CPC Class Codes: F16K 99/0044 : using thermo-electric means
• CPC Class Codes: F16K 99/0061 : actuated by an expanding gas or liquid volume
• CPC Class Codes: Y10S 366/04 : Micromixers: with application of energy to influence mixing/agitation, e.g. magnetic, electrical, e-m radiation, particulate radiation, or ultrasound
• CPC Class Codes: Y10T 137/1812 : In fluid flow path
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The movement and mixing of microdroplets through microchannels is described employing silicon-based microscale devices, comprising microdroplet transport channels, reaction regions, electrophoresis modules, and radiation detectors. The discrete droplets are differentially heated and propelled through etched channels. Electronic components are fabricated on the same substrate material, allowing sensors and controlling circuitry to be incorporated in the same device.

Claims

1. A method, comprising:

a) providing a channel defined within a generally planar substrate and having a liquid barrier, said barrier comprising a first silicon oxide layer, a silicon nitride layer, and a second silicon oxide layer, wherein said channel allows for movement of at least one liquid;

b) heating a mass of meltable material disposed adjacent to said channel within said substrate; and

c) moving said heated mass of meltable material into said channel, wherein said mass of meltable material is at least partially liquified.

2. The method of claim 1, wherein heating said mass of meltable material comprises a resistive element in thermal contact with said generally planar substrate.

3. The method of claim 2, wherein said resistive element is integral with said generally planar substrate.

4. The method of claim 1, wherein said at least one liquid is at least one discrete microdroplet having a volume of about 100 nanoliters or less.

5. The method of claim 1, wherein said channel has a cross-section of about 20 μ

m×

500 μ

m.

6. The method of claim 1, wherein said mass of meltable material comprises a material selected from the group consisting of wax, solder, polymer and plastic.

7. The method of claim 1, wherein said at least one liquid is moved along said channel into a reaction region, wherein said reaction region comprises an integral heater.

8. The method of claim 4, wherein said method further comprises merging a first discrete microdroplet with a second discrete microdroplet under conditions that said merged microdroplets are maintained as a heated mixture.

9. The method of claim 8, wherein said first liquid comprises a nucleic acid and said second liquid comprises a nuclease.

10. A method, comprising:

a) merging a first liquid and a second liquid within a channel defined within a generally planar substrate, said channel comprising a liquid barrier, wherein said barrier comprises a first silicon oxide layer, a silicon nitride layer, and a second silicon oxide layer;

b) heating a mass of meltable material disposed adjacent to said channel within said substrate; and

c) moving said heated mass of meltable material into said channel, wherein said mass of meltable material is at least partially liquified.

11. The method of claim 10, wherein said first liquid comprises a nucleic acid and said second liquid comprises a nuclease.

12. The method of claim 11, wherein said first liquid is a first discrete microdroplet and said second liquid is a second discrete microdroplet.

13. The method of claim 11, further comprising maintaining said first and second liquid as a heated mixture.