Pumpless microfluidics

• US 6,743,399 B1
• Filed: 10/06/2000
• Issued: 06/01/2004
• Est. Priority Date: 10/08/1999
• Status: Expired due to Term

• Current Assignee: Perkinelmer Health Sciences Incorporated (Perkinelmer Incorporated)
• Original Assignee: Micronics Inc. (Sony Group Corp.)
• Inventors: Hayenga, Jon W., Bardell, Ronald L., Schulte, Thomas E., Williams, Clinton L., Weigl, Bernhard H.
• Primary Examiner(s): Alexander, Lyle A.
• Assistant Examiner(s): HANDY, DWAYNE K
• Application Number:
  US09/684,094
• Time in Patent Office: 1,334 Days
• Field of Search: 422/61, 422/68.1, 422/99-102, 422/55, 422/58, 436/164, 436/165, 436/169, 436/174, 436/178, 436/180, 435/283.1, 435/287.1, 435/287.7, 435/287.8, 435/288.3, 204/400
• US Class Current: 422/504
• CPC Class Codes: B01F 25/433 Mixing tubes wherein the shape of the tube influences the mixing, e.g. mixing tubes with varying cross-section or provided with inwardly extending profiles
• CPC Class Codes: B01F 25/4331 Mixers with bended, curved, coiled, wounded mixing tubes or comprising elements for bending the flow
• CPC Class Codes: B01F 31/441 performing a rectilinear reciprocating movement
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 33/3039 with mixing achieved by diffusion between layers
• CPC Class Codes: B01F 33/451 wherein the mixture is directly exposed to an electromagnetic field without use of a stirrer, e.g. for material comprising ferromagnetic particles or for molten metal
• CPC Class Codes: B01L 2200/0636 Focussing flows, e.g. to laminate flows
• 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 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0822 Slides
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/0883 Serpentine channels
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0403 specific forces
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 2400/0457 : passive flow or gravitation
• CPC Class Codes: B01L 2400/0466 : Evaporation to induce underpressure
• CPC Class Codes: B01L 2400/0481 : squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0655 : pinch valves
• CPC Class Codes: B01L 2400/0688 : surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/5023 : with a sample being transported to, and subsequently stored in an absorbent for analysis
• 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: F15C 3/04 : using diaphragms using loose plates or foils F15C3/005; connection of valves to inflatable elastic bodies B60C29/00
• CPC Class Codes: F15C 3/06 : using balls or pill-shaped disks using fluid drops or similar deformable bodies F15C3/002
• CPC Class Codes: F16K 2099/0078 : using moulding or stamping
• 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 99/003 : Valves for single use only
• CPC Class Codes: F16K 99/0061 : actuated by an expanding gas or liquid volume
• CPC Class Codes: G01N 2035/00237 : Handling microquantities of analyte, e.g. microvalves, capillary networks
• CPC Class Codes: G01N 27/06 : of a liquid involving electrolysis G01N27/26
• CPC Class Codes: Y10T 436/25 : including sample preparation
• CPC Class Codes: Y10T 436/25625 : Dilution
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

A microfluidic device which operates without the need for an external power source. The device includes a body structure, at least one microscale channel within the structure, a port for introducing fluid into the channel, and a power source internal to the structure for propelling the fluid through the channel. Various structures are described which embody the invention.

Claims

1. A microfluidic device for joining two liquid streams when using gravitational force as a driving source, comprising:

a first reservoir for containing a first liquid, having a first outlet orifice;

a first channel having a first inlet opening coupled to said first orifice and a first outlet opening;

a second reservoir for containing a second liquid, having a second outlet orifice;

a second channel having a second inlet opening coupled to said second orifice and a second outlet opening;

a driving source, comprising gravitational force;

and a main microfluidic channel having an inlet coupling region for coupling said outlet openings of said first and second channels to said main channel, said inlet coupling region having a greater width than said main channel,

such that liquid driven by said gravitational force entering said coupling region from one of said first or second reservoirs through said channel outlet openings flows into said main microfluidic channel without trapping an air bubble within said other channel and blocking said outlet opening of said other channel.

2. The device of claim 1, wherein said inlet openings of said first and second channels comprise surface tension valves.

3. The device of claim 2, wherein the static resistance of said surface tension valves is lower than the dynamic resistance within said first and second channels.