Retaining microfluidic microcavity and other microfluidic structures
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).
1. A microfluidic device having 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 the structural unit is a 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 said manifold comprises
(a) a continuous microconduit containing an upper part at each end and therebetween alternating lower and upper parts, the number of upper parts is n and the number of lower parts is n−1 where n is an integer ≧3;
(b) a vent to ambient atmosphere and/or anti-wicking means in length-going edges delineating its lower wall(s) in each of the upper parts;
(c) an emptying opening in each of the lower parts which opening 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;
(d) a valve in each of the connecting microconduits;
(e) an inlet port which is connected to the continuous microconduit directly or indirectly at one of the upper parts; and
(f) an outlet port which is connected to the continuous microconduit directly or indirectly at an upper part that is not connected to said inlet port.
2. The microfluidic device of claim 1 , wherein the inlet port is connected to the continuous microconduit directly or indirectly at one of the end parts.
3. The microfluidic device of claim 1 , wherein the outlet port is connected to the continuous microconduit directly or indirectly at one of the end parts.
4. The microfluidic device of claim 1 , wherein the outlet port is connected to the continuous microconduit by a microconduit comprising an inner valve.
5. The microfluidic device of claim 1 , wherein each upper part comprises an upward bent.
6. The microfluidic device of claim 5 , wherein the inlet port and the outlet port of the structural unit are at a lower level than the extremes of the upward bents.
7. The microfluidic device of claim 1 , wherein each lower part comprises a downward bent.
8. The microfluidic device of claim 7 , wherein the downward bent is enlarged to a microcavity.
9. The microfluidic device of claim 1 , wherein the cross-sectional area along the continuous microconduit is of constant size and/or shape.
10. The microfluidic device of claim 1 , wherein the smallest cross-sectional area of the continuous microconduit is in each of the upper parts.
11. The microfluidic device of claim 1 , wherein the smallest cross-sectional area of the continuous microconduit is associated with the vent and/or the anti-wicking means in each of the upper parts.
12. The microfluidic device of claim 1 , wherein the inlet port and the outlet port of the structural unit are at a lower level than the extremes of the lower parts.
13. The microfluidic device of claim 1 , wherein the inlet port and the outlet port of the structural unit are at a lower level than any other parts of the microchannel structure that are downstream the lower part.
14. The microfluidic device of claim 1 , wherein a connecting microconduit and a lower part are connected by joints which are located at the same level.
15. The microfluidic device of claim 1 , wherein a connecting microconduit and a lower part are connected by joints, each of which are located at the lowest part of the lower part.
16. The microfluidic device of claim 1 , wherein the valve in the connecting microconduit or in the microconduit connecting the outlet port to the continuous microconduit is an inner valve.
17. The microfluidic device of claim 16 , wherein the valve is a capillary valve.
18. The microfluidic device of claim 16 , wherein the valve is a capillary valve comprising a hydrophobic surface break.
19. The microfluidic device of claim 1 , wherein the vents in the upper parts are located at the same level.
20. The microfluidic device of claim 1 , wherein the vent comprises anti-wicking means.
21. The microfluidic device of claim 1 , wherein each vent comprises a capillary valve and/or anti-wicking means which each is based on a hydrophobic surface break.
22. The microfluidic device of claim 1 , wherein the vents are connected to ambient atmosphere via a common venting channel.
23. The microfluidic device of claim 1 , wherein the device is spinnable about a spin axis and the microchannel structures and the structural unit arranged such that centrifugal force caused by spinning the device about the spin axis can be used for overcoming the valve functions.
24. The microfluidic device of claim 1 , wherein the device is in the form of a disc in which said microchannel structures.