Patent ID: 8372357

Claim:
A microfluidic device A) comprising a hydrophilic microchannel structure in which there is a functional unit that comprises: an upstream microcavity I with a liquid outlet I and capable of retaining a predetermined liquid volume defining an upper liquid level I in the microcavity, a microconduit I that has an inlet end connected to liquid outlet I, an outlet end and an upward turn that comprises an upper extreme that is above the level of the inlet end of microconduit I, and a capillary valve I that is associated with microconduit I, and B) being capable of spinning about a spin axis to create centrifugal force that can assist in transporting liquid from said upstream microcavity into and/or through microconduit I, wherein (i) the inlet end of microconduit I is closer to the spin axis than the outlet end of microconduit I, (ii) capillary valve I is positioned in microconduit I at, or upstream of, the upper extreme, and (iii) the upstream microcavity has an upper part and a lower part and liquid outlet I is positioned between said upper part and said lower part, wherein there is no valve between said lower part and said upper part.