on electromechanical property of piezo ceramic to deform in response to applied voltage. Piezoelectric disk attached to the membrane causes diaphragm deflection driven by the external axial electric field thus expanding and contracting the chamber of the micropump. This mechanical strain results in pressure variation in the chamber, which causes inflow and outflow of the fluid. The flow rate is controlled by the polarization limit of the material and the voltage applied on the piezo. In comparison with other actuation principles piezoelectric actuation enables high stroke volume, high actuation force and fast mechanical response, though requiring comparatively high actuation voltage and complex mounting procedure of the piezo ceramic. The smallest piezoelectric micropump with dimensions of 3.5x3.5x0.6 mm3 was developed by Fraunhofer EMFT the world-renowned research organization with focus on MEMS and Microsystem technologies. The micropump consists of three silicon layers, one of which as a pump diaphragm confines the pump chamber from above, while two others represent middle valve chip and bottom valve chip. Openings of the passive flap valves at the inlet and outlet are oriented according to the flow direction. The pump diaphragm expands with application of a negative voltage to the piezo thus creating negative pressure to suck the fluid into the pump chamber. While positive voltage vice versa drives the diaphragm down, which results in overpressure opening outlet valve and forcing the fluid out of the chamber. Currently mechanical micropump technology extensively uses Silicon and Glass based micromachining processes for fabrication. Among the common microfabrication processes, the following techniques can be named: photolithography, anisotropic etching, surface micromachining and bulk micromachining of silicon. Silicon micromachining has numerous advantages that facilitate the technology widespread in high performance applications as, for example, in drug delivery. Thus, silicon micromachining allows high geometric precision and long-term stability, since mechanically moving parts, e.g. valve flaps, do not exhibit wear and fatigue. As an alternative to silicon polymer-based materials like PDMS, PMMA, PLLA, etc. can be used due to the superior strength, enhanced structural properties, stability and inexpensiveness. Silicon micropumps at Fraunhofer EMFT are manufactured by silicon micromachining technology. Three monocrystalline silicon wafers (100 oriented) are structured by doublesided lithography and etched by silicon wet etching (using potassium hydroxide solution KOH). The connection between the structured wafer layers is realized by silicon fusion bond. This bonding technology needs very smooth surfaces (roughness lower than 0.3 nm) and very high temperatures (up to 1100