Microfluidics and microreaction technology constitute an upcoming field in a variety of industrial branches. As this technique is implemented in the daily business of industrial companies the cost-effectiveness of the production process starts to become an issue. The micro metal injection molding (mu-MIM) process provides freedom of design for a broad spectrum of materials ( metals, metal alloys, and polymers). Catalytic as well as bio-compatible materials have already been structured using this technology. Furthermore, mu-MIM shows the potential of a cost-effective production technique that can be adapted to produce microstructured parts for various applications. As a case example a microfluidic structure was applied for water purification. The reactor surface was coated with an active photocatalytic (TiO2) modified nano-layer using dip coating. Subsequently, it was covered with a glass plate adhered with a two-component adhesive. For determination of hydrodynamics, measurements by means of mu PTV have been performed. For investigations of water purification and sanitization the reactor was first fed with a water stream contaminated by a special dye to optimize the hydrodynamic parameters and afterwards with a water stream contaminated by Escherichia coli to investigate the degradation of germs. This was done by illuminating the TiO2-coated reactor with UV light. The results indicate that this new type of reactor has an exceptional high potential to eliminate germs in drinking water.