The invention relates to a design of an interface plate (101) between a microfluidic cartridge (100) and an instrument (102) for fluid actuation in the disposable cartridge. Pneumatic actuation is carried out through a reversible pneumatic interconnection between instrument and cartridge. Pneumatic drivers are integrated in the instrument for a low cost and reliable solution. The actuation of the fluid in the cartridge is achieved by a flexible membrane (105) attached to the major surface of the disposable cartridge forming closed compartments only when attached to the instrument. The pressure, in these compartments determines the deflection of the membrane which in turn actuates the fluid. This approach takes advantage of the high power and large stroke of pneumatic actuation while at the same time keeping the disposable cartridge simple and low cost and allowing easy introduction of other physical transport across the interface plate, like heat or acoustic vibration. A large number of actuators can be integrated easily into the flat interface plate as no individual fixation, like tubing, is required for the pneumatic actuation.