An apparatus for controlling the flow of fluids through microfluidic channels, process for their operation, and their use

The invention relates to a device for controlling the flow of fluids through n> 1 microfluidic channels 9, 10, ..., 16 that are introduced into a substrate 3 and configured such that each channel in each case m ≧ 1 contact points each with a heating element 40-1, 40-2, ..., 45-4 having wherein - for at most the first half of the channels respectively for each channel herewith is in contact heating element is connected by a first conductor track 40, 42, 44, each with a heating element of the other channels, - for a maximum of the other half of the channels respectively for each channel herewith is in contact heating element is connected by a second conductive path 41, 43, 45, each with a heating element of the other channels, - a respective first conductor track 40, 42, 44 and a second conductive path 41, 43, 45 combined in pairs in each case form, for which only the switching state of TRUE or only the switching state FALSE is either set a control line 50, 51, 52, and - the conductor tracks 40, 41, ..., 45 and heating elements 40-1, 40-2, ..., 45-4 are located on a circuit board 2 which is adjacent to a cooling element. 8 The invention further relates to a method for operating the apparatus and their use for the control of liquids, in particular aqueous solutions, intermediary or separation media for applications in medical technology or biotechnology.