This paper reports the design, fabrication and testing of silicon based micropump for liquid and gases. This piezoelectrically driven membrane pump is designed to be tolerant to gas-bubbles and to be suitable for self-priming. Reducing the dead volume within the pump, and thus increasing the compression ration, achieves the gas pumping. The main advantage of the pump described in the paper is the self-aligning of the membrane unit to the valve unit and the possibility of using screen printed PZT as actuator, which enables mass production and thus very low-cost micropumps. Dynamic passive valves are used, as those valves are very reliable having no moving parts and being not sensitive to smaller particles. Furthermore they can follow high frequencies, hence allowing the pump to run at resonance frequency enabling the maximum deflection of the diaphragm. First tests carried out on the micropump have produced promising results.