Abstract: A microfluidic device includes a first microchannel, a second microchannel, and a valve comprising at least an input port and an output port, the ports respectively connected to the first microchannel and the second microchannel, the valve designed to control a flow of a liquid along a flow direction (z) defined by the ports; wherein the valve further comprises one or more walls joining the ports and defining a hollow chamber that is wider than each of the microchannels in a direction perpendicular to the flow direction, the walls at least partly deformable along a deformation direction (?y) intersecting the flow direction, such that the walls can be given at least a first deformation state and a second deformation state, such that the liquid can be pulled along the flow direction substantially more in the second deformation state than in the first deformation state.