Moving microdroplets

• US 6,911,183 B1
• Filed: 03/06/2000
• Issued: 06/28/2005
• Est. Priority Date: 09/15/1995
• Status: Expired due to Term

• 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: Handique, Kalyan, Burns, Mark A., Gogoi, Bishnu
• Primary Examiner(s): Ludlow, Jan M.
• Application Number:
  US09/518,895
• Time in Patent Office: 1,940 Days
• Field of Search: 422/56, 422/58, 422/81, 422/82, 422/102, 422/100, 436/52, 436/53, 436/180
• US Class Current: 422/502
• 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: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• 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 2400/0688 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 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• 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: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 : Manufacture or treatment of nanostructures
• CPC Class Codes: F15B 13/0807 : Manifolds
• CPC Class Codes: F16K 2099/0074 : using photolithography, e.g. etching
• 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 99/0019 : Valves using a microdroplet or microbubble as the valve member
• CPC Class Codes: F16K 99/0061 : actuated by an expanding gas or liquid volume
• CPC Class Codes: Y10T 436/117497 : with a continuously flowing sample or carrier stream
• CPC Class Codes: Y10T 436/118339 : with formation of a segmented stream
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The movement and mixing of microdroplets through microchannels is described employing 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 device comprising first and second side channels attached to a microdroplet transport channel etched in substrate so as to create first and second intersections, said first and second side channels having hydrophobic surfaces said microdroplet transport channel comprising a hydrophobic region and liquid abutting said hydrophobic region, said liquid extending through said first intersection without entering said first side channel wherein said hydrophobic region is positioned in said microdroplet transport channel between said first and second side channels.

2. The device of claim 1, wherein said microdroplet transport channel is between 5 and 20 μ

m in depth and between 20 and 1000 μ

m in width.

3. A device comprising first and second side channels attached to a microdroplet transport channel so as to create first and second intersections, said first and second side channels having hydrophobic surfaces, said microdroplet transport channel comprising i) first and second ends, said first end comprising a liquid inlet port ii) a hydrophobic region disposed within said microdroplet transport channel between said first and second ends, and iii) liquid extending from said inlet port through said first intersection, without entering said first side channel, and abutting said hydrophobic region.

4. The device of claim 3, wherein said device is fabricated from a glass, quartz or silicon substrate.

5. The device of claim 3, wherein said microdroplet transport channel is between 5 and 20 μ

m in depth and between 20 and 1000 μ

m in width.