Functional surfaces often require structures that enhance the intrinsic properties of the materials or cause a particular physical or optical effect due to the structures’ dimension. For this purpose, nanostructures are required, which can be produced reproducibly and at high speed by means of pulsed laser radiation. When laser ablation technology is used, the highest surface accuracies can be achieved wherein periodic structures in the range from 100 nm to 1000 nm can be applied to components by the so-called multi-beam interference technology.
With special optics, the periodicities and nanomodes can be adjusted selectively and generated by the interference of several partial beams. Two-, three- and four-beam interferences are possible, in which different patterns can be generated by choosing the polarization systematically. Since interferences occur on the surfaces, certain interference colors can be generated both on components and on tools, which can be transferred to large components by means of replication processes such as embossing and injection molding.
In addition to the deterministic nanostructures, self-organization effects in the processing with ultrafast pulsed lasers make it possible to generate nanostructures in the range of 100 to 500 nm. Depending on the pulse duration and wavelength, functional structures can be generated on metals and transferred to metallic films and polymers by high speed replication processes.
Thanks to its extensive and modern equipment as well as its in-depth know-how, Fraunhofer ILT and Fraunhofer IWS facilitate applied research on micro- and fine-machining with laser beams so that functional elements can be miniaturized for use in machine, plant, vehicle and device construction as well as in biotechnology and medical technology.