Rapid prototyping of micro-fluidic components by laser beam processing

As a sequential production method, laser technology is considered not to be a competitor to established plastic processing methods, but instead is used whenever small numbers or just mere prototypes are required. Laser ablation by UV-excimer lasers is a flexible and accurate tool for the manufacturing of polymeric micro-fluidic parts. Even soft and flexible materials like PDMS that are difficult to machine with conventional techniques can be structured by laser ablation with great precision and quality. Sealing of polymer parts by laser beam welding leads to a complete production cycle for small series and prototypes. A further application of UV-excimer lasers is the production of so called "lost moulds" for the production of filigree microstructures. Micro-pillars are fabricated by drilling holes in wax masters using excimer laser radiation and subsequent casting with PDMS. Frictionless demolding is achieved by melting the wax away. The fabricated PDMS micro-pillar arrays can be used for shear stress and flow rate sensors due to bending of the flexible posts. In combination with laser ablation techniques micro-fluidic devices with new properties can be fabricated