Combining micro-milling and laser structuring for manufacturing complex micro-fluidic structures

Miniaturization has become one of the most important keywords for production technologies in the last years. Whether in microelectronics, medical engineering or production engineering, parts and assemblies are becoming smaller to provide a higher functionality in the same space or smaller. In the field of micro production technology, this means adapting established production technologies for the generation of small devices, structures and also the development of new technologies based upon ablation processes. The department for precision technology and micro-manufacturing of the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz deals with the implementation of these processes particularly with regard to manufacturing-oriented process design in the fields of automotive, medical and production engineering. A distinctive application example for the use of different micro manufacturing processes is micro fluidics, for example in the employment of medical sensors, where the goal is to produce micro fluidic structures with feature sizes < 10 µm and a processing accuracy of around 1-2 µm ; and in large quantities. Hot embossing enables a fast and economic replication of these micro fluidic elements, but requires a master structure to be produced on a mould surface that can be pressed into substrate at an elevated temperature, forming a negative relief replica of the master topography. Thereby quite different materials like plastics, metal and glass can be structured with a high reliability.