Retaining microfluidic microcavity and other microfluidic structures

• US 7,275,858 B2
• Filed: 12/13/2004
• Issued: 10/02/2007
• Est. Priority Date: 08/28/2001
• Status: Expired due to Term

• Current Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Original Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Inventors: Andersson, Per, Helene, Derand
• Primary Examiner(s): SOOHOO, TONY GLEN
• Application Number:
  US11/010,870
• Publication Number:
  US 20050153432A1
• Time in Patent Office: 1,023 Days
• Field of Search: 366/341, 366/DIG.4, 422/99, 422/100
• US Class Current: 366/341
• 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 25/4338 Mixers with a succession of converging-diverging cross-sections, i.e. undulating cross-section
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 35/71 Feed mechanisms with proportioning B01F35/80
• CPC Class Codes: B01F 35/712 for feeding fluids
• CPC Class Codes: B01F 35/7172 using capillary forces
• CPC Class Codes: B01F 35/71725 using centrifugal 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 2219/00536 in the shape of disks
• CPC Class Codes: B01J 2219/00725 Peptides
• CPC Class Codes: B01J 2219/00738 Organic catalysts
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/06 Fluid handling related problems
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• 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 2200/142 Preventing evaporation
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2300/0803 Disc shape
• CPC Class Codes: B01L 2300/0806 Standardised forms, e.g. compact disc [CD] format
• CPC Class Codes: B01L 2300/0861 : Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2300/087 : Multiple sequential chambers
• CPC Class Codes: B01L 2300/14 : Means for pressure control
• CPC Class Codes: B01L 2300/16 : Surface properties and coatings
• CPC Class Codes: B01L 2400/0409 : centrifugal forces
• CPC Class Codes: B01L 2400/0418 : electro-osmotic flow [EOF]
• CPC Class Codes: B01L 2400/0633 : with moving parts
• CPC Class Codes: B01L 2400/0688 : surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/5025 : for parallel transport of multiple samples
• CPC Class Codes: B01L 3/5027 : by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502738 : characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: C40B 40/10 : Libraries containing peptides or polypeptides, or derivatives thereof
• CPC Class Codes: G01N 2035/00504 : combined with carousels
• CPC Class Codes: G01N 30/466 : with separation columns in parallel
• CPC Class Codes: G01N 30/6095 : Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: G01N 33/54366 : Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 35/00069 : whereby the sample substrate is of the bio-disk type, i.e. having the format of an optical disk
• CPC Class Codes: H01J 49/04 : Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components
• 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

Abstract

A microfluidic device that comprises several microchannel structures in which there are an inlet port, an outlet port and there between a structural unit comprising a fluidic function. The structural unit can be selected amongst units enabling a) retaining of nl-aliquots comprising constituents which has been defined by mixing of aliquots within the microfluidic device (unit A), b) mixing of aliquots of liquids (unit B), c) partition of larger aliquots of liquids into smaller aliquots of liquids and distributing the latter individually and in parallel to different microchannel structure of the same microfluidic device (unit C), d) quick penetration into a microchannel structure of an aliquot of a liquid dispensed to an inlet port of a microchannel structure (unit D), and e) volume definition integrated within a microchannel structure (unit E).

Claims

1. A microfluidic device comprising a microchannel structure in which there are one or more inlet ports, one or more outlet ports, and a structural unit in communication with at least one of said ports, wherein said structural unit is an integrated volume defining unit that enables volume-definition of an aliquot of liquid within the microchannel structure and which said volume defining unit comprises:

a) a volume-defining microcavity;

b) an inlet microconduit which is connected to the microcavity via an inlet opening of the microcavity;

c) an outlet microconduit which is connected to the microcavity via an outlet opening of the microcavity with a valve at the joint between the outlet microconduit and the microcavity; and

d) an overflow microconduit, which is connected to an overflow opening of the microcavity which overflow opening is at the same level as the joint between the inlet microconduit and the volume defining microcavity, the microcavity being constricted at the overflow opening;

wherein the overflow opening is at a higher level than the outlet opening and the volume being defined as the volume between the valve and the overflow opening.

2. The microfluidic device of claim 1, wherein the volume of the volume-defining microcavity is ≦

100 μ

l.

3. The microfluidic device of claim 1, wherein the volume of the volume-defining microcavity is ≦

5,000 nl.

4. The microfluidic device of claim 1, wherein the overflow microconduit is communicating with ambient atmosphere via an enlargement in the form of a waste conduit or waste chamber that is located at the end of the overflow microconduit.

5. The micro fluidic device of claim 1, wherein the inlet opening of the volume-defining microcavity is at the same level as the overflow opening.

6. The microfluidic device of claim 5 wherein the volume-defining microcavity is a downwardly bent microconduit with

a) one shank acting as inlet, and

b) the other shank

(i) ending in an upward bent functioning as the overflow microconduit, and

(ii) venting to ambient atmosphere, and

the outlet microconduit being joined at the lower part of the downwardly bent microconduit.

7. The microfluidic device of claim 6, wherein said other shank is designed with an inlet function for liquid.

8. The microfluidic device of claim 1, wherein the outlet opening of the volume-defining microcavity is above the lowest part of the volume-defining microcavity.

9. The microfluidic device of claim 1, wherein the ratio a₁/a₂ is ≧

⅓

where a₁ is the cross-sectional area of the volume-defining microcavity at the overflow opening and a₂ is the largest cross-sectional area between the overflow opening and the outlet opening.

10. The microfluidic device of claim 1, wherein the inlet microconduit widens to an inlet port.

11. The microfluidic device of claim 1, wherein there is a valve function associated with the overflow microconduit.

12. The microfluidic device of claim 11, wherein the overflow microconduit ends in a waste chamber or waste microconduit and the valve function in the overflow microcoduit is associated with the joint between the overflow microconduit and the waste chamber or waste microconduit.

13. The microfluidic device of claim 1, wherein the valve at the outlet microconduit and the valve associated in the overflow microconduit are capillary valves.

14. The microfluidic device of claim 13, wherein at least one of said capillary valves comprises a hydrophobic surface break.

15. The microfluidic device of claim 1, wherein at least one of the inlet microconduit, the outlet microconduit and the overflow microconduit comprises anti-wicking means in the form of a change in geometrical and/or chemical surface characteristics.

16. The microfluidic device of claim 1, wherein at least one of the inlet microconduit, the outlet microconduit and the overflow microconduit comprises anti-wicking means comprising an indentation and/or a protrusion and/or a hydrophobic surface break.

17. The micro fluidic device of claim 1, wherein the liquid is aqueous.

18. The microfluidic device of claim 1, wherein the inner surfaces of the structural unit have a wettability permitting capillary force to draw liquid into the unit once the liquid has passed the entrance of the unit.

19. The microfluidic device of claim 1, wherein the device is in the form of a disc and comprises two or more of the microchannel structures.

20. The microfluidic device of claim 1, wherein the microchannel structure is oriented from an inner position to an outer position relative to a spin axis enabling centrifugal force created by spinning the device about the spin axis to drive liquid placed in the microchannel structure through at least a part of the microchannel structure.