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...http://www.google.de/patents/US7429354?utm_source=gb-gplus-sharePatent US7429354 - Structural units that define fluidic functions
