Retaining microfluidic microcavity and other microfluidic structures

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 ≧2;
• (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.

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 an inlet port which promotes penetration from an inlet opening into the microchannel structure and said inlet port comprises:

• a) a microcavity;
• b) an inlet opening
• c) an inlet microconduit located downstream said microcavity and in communication with the interior of the microchannel structure;
• and
• d) one, two or more grooves and/or ridges in the inner wall of the microcavity which grooves and/or ridges are directed towards the connection between the microcavity and the inlet microconduit.

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 the integrated volume defining unit that enables volume-definition of an aliquot 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 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.