Structural units that define fluidic functions

• US 20040120856A1
• Filed: 02/16/2004
• Published: 06/24/2004
• Est. Priority Date: 03/19/2001
• Status: Active Grant

• Current Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Original Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Inventors: Andersson, Per, Thorsen, Gunnar, Ekstrand, Gunnar, Derand, Helene, Wallenborg, Sussanne, Togan-Tekin, Ebru, Selditz, Ulrike
• Granted Patent: US 7,429,354 B2
• Time in Patent Office: Days
• US Class Current: 422/72
• 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 2200/0678 Facilitating or initiating evaporation
• CPC Class Codes: B01L 2200/0684 Venting, avoiding backpressure, avoid gas bubbles
• CPC Class Codes: B01L 2300/0806 Standardised forms, e.g. compact disc [CD] format
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/5025 for parallel transport of multiple samples
• CPC Class Codes: B01L 3/502723 characterised by venting arrangements
• 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 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• 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

Abstract

A microfluidic device that comprises several microchannel structures in which there are an inlet port, an outlet port and therebetween a substructure comprising a fluidic function. The device has an axis of symmetry around which the microchannel structures are arranged as two or more concentric annular zones for an inlet port and an outlet port of the same microchannel structure the inlet port is typically closer to the axis of symmetry than the outlet port. Each microchannel structure comprises a substructure that can retain liquid while the disc is spun around the axis and/or the inlet ports are positioned separate from the paths waste liquid leaving open waste outlet ports will follow across the surface of the disc when it is spun. For the microchannel structures of an annular zones the corresponding substructures are at essentially at the same radial distance while corresponding substructures in microchannel structures of different annular zones are at different radial distances. The invention also refers to several other substructures. The substructure are primarily adapted for transporting liquid aliquots that have a surface tnsion >5 mN/m with centrifugal force.

Claims

1. A microfluidic device that comprises a microchannel structure in which there are (a) one or more inlet ports, (b) one or more structural units downstream one of the inlet ports, and (c) one or more outlet ports, characterized in that the microfluidic device comprises a plurality of individual microchannel structures (501a,b,c) which are

(i) present in a substrate having a spinning axis;

and

(ii) arranged to define two or more annular zones (rings) (504) or sectors thereof around the spinning axis

with each microchannel structure (501a,b,c) having a substructure (506a,b,c) which is downstream the inlet port (505a,b,c) and which is capable of retaining liquid when the substrate is spun; and

/or

with inlet ports being located separate from the paths waste liquid aliquots leaving the open waste outlet ports will follow across the surface of the disc when it is spun,

each of said annular zones/rings or sectors thereof has microchannel structures in which corresponding substructures are present at the same radial distance while corresponding substructures, if any, of other zones/rings are present at other radial distances.

2. A microfluidic device comprising a microchannel structure in which there are (a) one or more inlet ports, (b) one or more structural units downstream one of the inlet ports, and (c) one or more outlet ports, characterized in that the structural unit is selected amongst units 1-12 as in defined in the previous text.

4. The microchannel structure of claim 2, characterized in that one of said units is unit 2 and enables mixing of two liquid aliquots (aliquot 1 and aliquot 2) that are miscible with each other, and which comprises:

(a) a microcavity (303) with an outlet opening (323);

(b) an inlet arrangement (301) linked to the microcavity (303), and

(c) a mixing microconduit (302) connected to the outlet opening (323).

5. The microfluidic device of claim 2, characterized in that one of said units is unit 3, 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 (401) containing an upper part at each end (402, 403) (end parts) and therebetween alternating lower and upper parts (404a,b,c etc and 405a,b,c etc, respectively);

(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 (402, 403, 405a,b,c etc) has a vent (top vent) (406) to ambient atmosphere;

(d) each of the lower parts (404a,b,c etc) has an emptying opening which in a downstream direction via a connecting microconduit (407) communicates with the remaining substructure of the microchannel structure or with the corresponding substructure of another microchannel structure (see FIGS. 3a-b);

(e) each of the connecting microconduits (407) has a valve (408);

(f) an inlet (409) is connected to the continuous microconduit (401) directly or indirectly at one of the upper parts (402, 403, 405a,b,c etc), preferably via one of the end parts (402 or 403);

(g) an outlet port (410) is connected to the continuous microconduit (401) directly or indirectly at another upper part (402, 403, 405a,b,c etc), preferably via one of the end parts (402 or 403).

6. The microfluidic device of claim 2, characterized in that one of said units is unit 5 which and enables transport of an aliquot of a liquid back and forth between two microcavities within the unit, and comprises:

(a) two microcavities (601 and 602) and a microconduit (603) connecting microcavity (601) and microcavity (602) to each other;

Microcavity (601) may or may not be widening from microconduit (603) and typically has one or more edges which pass into the inner wall of microconduit (603); and

Microcavity (602) may or may not be widening from microconduit (603); and

Microconduit (603) may be narrowing or have constant cross-sectional area or shape in the part next to microcavity (601), possibly with a length-going edge directed towards microcavity (602) and possibly starting in microcavity (601).

(b) an inlet opening (604) which in the upstream direction communicates with an inlet port, and an outlet opening (605) which in the downstream direction communicates with an outlet port;

(c) a vent (606) to ambient atmosphere in a dead end, if present, of the unit; and

(d) a valve function (607) associated with the outlet opening (605).

7. The microfluid device of claim 2, characterized in that one of said units is unit 6 which promotes controlled evaporation of a liquid aliquot, and comprises

(a) an outlet port (701) that has an opening (702) and a well (703), and

(b) an incoming microconduit (704) that enters the well (703) and in the upstream direction communicates with an inlet port.

8. The microfluidic device of claim 2, characterized in that one of said units is unit 7, which provides anti-wicking means for a liquid which is present in the unit, and comprises a microconduit (801) which is in direct communication with a microcavity (802) and contains one, two or more length-going inner edges that start at or within the microcavity (802),

(a) a change in geometric surface characteristics (804,810,811) being present in a zone outside the microcavity and associated and in at least one of said one, two or more edges,

(b) an optional change in the chemical surface characteristics (805, surface break)

which is physically associated with said change in geometric surface characteristics

in the same edge or is present in a zone of another edge.

9. The microfluidic device of claim 2, characterized in that one of said units is unit 8, which is capable of creating a front zone of liquid (liquid 1) of different composition compared to the bulk liquid (liquid 2), said unit comprises

(a) a microconduit (901) for transport of the bulk liquid (liquid 2) and having an inlet end (902), and an outlet end (903);

and

(b) along the microconduit (901) an opening (904) into a microcavity (905) comprising the liquid (liquid 1) with the proviso that liquid 1 (906) fills up the microcavity (905) so that its meniscus (907) is present in the opening (904).

10. The microfluidic device of claim 2, characterized in that one of said units is unit 9 which comprises

(a) a microconduit (1001) having a defined flow direction (1002, arrow),

(b) preferably being connected to a microcavity/microchamber (1003) and comprising a circumferential zone (1004) in which there is a non-closing inner valve function which function defined by

(i) a change in geometric surface characteristics (1005) in at least one sidewall (1006) within the zone, and

(ii) at least one sidewall (1007) not having the change in geometric surface characteristics being non-wettable, preferably a sidewall opposing a sidewall having a change in geometric surface characteristics.

11. The microfluidic device of claim 2, characterized in that one of said units is unit 10, which promotes penetration from an inlet opening into the microchannel structure and comprises:

(a) an inlet port comprising a microcavity (1101) and an inlet opening (1102),

(b) downstream said microcavity (1101) an inlet conduit (1103) communicating into the interior of the microchannel structure, and

(c) one, two or more grooves and/or projections (rills) (1104) in the inner wall of the microcavity (1101) and directed towards the connection between the inlet conduit (1103) and the microcavity (1101).

12. The microfluidic device of claim 2, characterized in that one of said units is unit 11 and enables volume-definition of a liquid aliquot within the microchannel structure and comprises

(a) a volume-defining microcavity (1201),

(b) an inlet microconduit (1202) which is connected to the microcavity (1201) via an inlet opening on the microcavity (1201),

(c) an outlet microconduit (1203) which is connected to microcavity (1201) via an outlet opening in microcavity (1201) with a valve (1206) at the joint between the outlet microconduit (1203) and microcavity (1203), and

(d) an overflow microconduit (1204), which is connected to an overflow opening on microcavity (1201), the microcavity (1201) preferably being constricted at the joint between the overflow microconduit (1204) and the microcavity (1201);

the overflow opening is at a higher level than the outlet opening (1203) and the volume being defined as the volume between valve (1206) and the joint between the overflow microconduit (1204) and the microcavity (1201).

13. The microfluidic device of claim 2, characterized in that the unit is unit 12 and enables physical separation of particular materials from a liquid aliquot and comprises:

a microcavity (1301) in which there are;

(a) a lower part (1302) for particulate material,

(b) an upper part (1303) for liquid free of particulate material,

(c) an inlet opening (1304) in the upper part of the microcavity, and

(d) an outlet opening (1305) above the lower part (1302) of the microcavity but below the inlet opening (1304);

said outlet opening (1305) communicating via an outlet conduit (1307) with a functiona/structural unit in which a component of liquid which is free from particulate material can be further processed, and

said outlet conduit (1307) preferably comprising a valve function associated with the outlet opening (1305).

3. The microfluidic device of claim, characterized in that one of said units is unit 1 which enables selectively directing a first liquid aliquot (aliquot 1) into one branch and a subsequent liquid aliquot (aliquot 2) into another branch of an incoming microconduit and comprises

(a) an incoming microconduit (201) which in its downstream part divides into at least two microconduit branches (202,203) at a branching point (204), and

(b) an inner valve function (205a,b) associated with one or both of the branches (202,203).