Retaining microfluidic microcavity and other microfluidic structures

• US 20030044322A1
• Filed: 08/28/2002
• Published: 03/06/2003
• Est. Priority Date: 08/28/2001
• Status: Active Grant

• Current Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Original Assignee: Gyros AB (Mesa Laboratories Inc.)
• Inventors: Andersson, Per, Ekstrand, Gunnar
• Granted Patent: US 6,919,058 B2
• Time in Patent Office: Days
• US Class Current: 422/100
• 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 35/712 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 one or more structural units wherein said structural unit comprises:

(a) a retaining microcavity which is located between one of said one or more inlet ports and one of said one or more outlet ports;

(b) a mixing unit which is located upstream the retaining microcavity and downstream said one inlet port;

(c) two or more microconduits directly connected to the retaining microcavity and communicating with one of said inlet or outlet ports;

wherein one or more of said microconduits comprise anti-wicking means in association with the joint between the retaining microcavity and the microconduit and/or the distance (d₁) from the retaining microcavity to an opening to ambient atmosphere and including a microconduit that lacks anti-wicking means and is directly attached to the retaining microcavity, is ≧

20 times the largest inner cross-sectional dimension of the microconduit at its joint to the retaining microcavity.

2. The microfluidic device of claim 1, wherein the microconduit comprising anti-wicking means is a liquid flow microconduit and a microconduit lacking anti-wicking means is an air microconduit.

3. The microfluidic of claim 1, wherein at least one microconduit comprises an anti-wicking means having

(a) one or more length-going edges extending continuously from said retaining microcavity or

(b) a change in geometric and/or chemical surface characteristics in at least one of said one or more edges.

4. The microfluidic device of claim 3, wherein said geometric change is in the form of an indentation.

5. The microfluidic device claim 3, wherein said change in chemical surface characteristics is a hydrophobic surface break when going in a microconduit from the retaining microcavity which has hydrophilic inner surfaces.

6. The microfluidic device of claim 3, wherein said change in geometric and/or chemical surface characteristics is extending between two edges delineating an inner wall.

7. The microfluidic device of claim 1, wherein at least one of said microconduit comprises a non-closing valve function essentially at its joint with the retaining microcavity, said valve function preferably at least partially coinciding with the anti-wicking means of said at least microconduit.

8. The microfluidic device of claim 7, wherein said valve function is a hydrophobic surface break at the valve function, and/or a capillary barrier caused by a change in geometric surface characteristics, and/or the curvature in the microconduit comprising the valve function.

9. The microfluidic device of claim 1, wherein said mixing unit comprises at least two inlet microconduits for said two or more liquid aliquots to be mixed.

10. The microfluidic device of claim 1, wherein the device comprises a plurality of said microchannel structure.

11. The microfluidic disc of claim 10, wherein the disc comprises

(a) the device having an axis of symmetry coinciding with a spinning axis,

(b) each of said microchannel structures is arranged relative to said axis with a downstream part more remote to said axis than an upstream part, and

(c) application of centrifugal force by spinning the device about said axes being capable of forcing a liquid aliquot that is present in each of said microchannel structures to be transported in parallel in the downstream direction within said microchannel structure.

12. 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 having at least one of said ports, wherein the structural unit is selected from the group consisting of mixing unit, distribution manifold, inlet port and integrated volume-defining unit.

13. The microchannel device of claim 12, wherein one of said units is a mixing unit and enables mixing of two aliquots that are miscible with each other, and which comprises:

a microcavity with an outlet opening;

an inlet arrangement linked to the microcavity, and a mixing microconduit connected to the outlet opening.

14. The microfluidic device of claim 12, wherein one of said units is the distribution manifold which enables partition of a larger portion of liquid into smaller aliquots which subsequently are introduced in parallel into downstream parts of separate microchannel structures, and which comprises

(a) a continuous microconduit ontaining an upper part at each end and therebetween alternating lower and upper parts;

(b) the number of upper parts is n and the number of lower parts is n-1 where n is an integer ≧

2;

(c) each of the upper parts has a vent to ambient atmosphere and/or anti-wicking means in length-going edges delineating its lower wall(s);

(d) each of the lower parts has an emptying opening which in a downstream direction via a connecting microconduit communicates with the remaining substructure of the microchannel structure or with the corresponding substructure of another microchannel structure;

(e) each of the connecting microconduits has a valve;

(f) an inlet is connected to the continuous microconduit directly or indirectly at one of the upper parts, preferably via one of the end parts; and

(g) an outlet port is connected to the continuous microconduit directly or indirectly at another upper part.

15. The microfluidic device of claim 12, wherein one of said units the inlet port which promotes penetration from an inlet opening into the microchannel structure and comprises:

a) an inlet port comprising a microcavity; and

b) an inlet opening, downstream said microcavity an inlet conduit communicating into the interior of the microchannel structure; and

c) one, two or more grooves and/or projections in the inner wall of the microcavity and directed towards the connection between the inlet conduit and the microcavity.

16. The microfluidic device of claim 12, characterized in that one of said units is the integrated volume defining unit and enables volume-definition of an aliquot within the microchannel structure and comprises:

a) a volume-defining microcavity;

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

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

d) an overflow microconduit, which is connected to an overflow opening on microcavity, the microcavity preferably being constricted at the joint between the overflow microconduit and the microcavity;

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