A microfluidic device is described. The microfluidic device comprises at least one transport channel and at least one working chamber, wherein the at least one transport channel and the at least one working chamber are separated from each other by a common deformable wall. The at least one transport channel is for containing a transport fluid and the at least one working chamber is for containing a working fluid. The microfluidic device comprises at least one pair of electrodes for changing the pressure on the working fluid such that when the pressure on the working fluid is changed, the deformable wall deforms, resulting in a change of the cross-section of the at least one transport channel. The working chamber comprises a flexible wall different from the common deformable wall and at least one electrode of the at least one pair of electrodes is provided on the flexible wall.