Compact Surface Functionalization
Generation of Targeted Surface Topographies
Functionalization of technical surfaces by means of natural, bio-inspired structures is an innovation driver of the 21th century. The functionalities achieved are applicable for e.g. improved bio-compatibility in medical and biotechnological industries, for tribological applications in the automotive industry and for optical applications such as product and brand protection. With respect to novel, targeted surface functionalities, an efficient generation of nano- and micrometer sized structures is the greatest challenge. Established manufacturing methods such as electron beam lithography or direct laser inscription are either too cost and time consuming or only allow low structure resolution.
Fraunhofer Institute for Material and Beam Technology IWS Dresden, Germany, has been developing modularly designed solutions for surface functionalization tasks by fabricating micrometer and sub-micrometer structures in a targeted and flexible manner. Scientists of the Fraunhofer IWS can now present for the very first time the worldwide most compact system for surface structuring by means of scanner-based direct laser interference patterning.
High Process Speed
The direct laser interference patterning (DLIP) technology developed at Fraunhofer IWS offers a flexible industrial tool for the generation of targeted surface topographies for numerous applications. In DLIP, a coherent laser beam is split into two or more sub-beams, which are superposed on the materials surface. Defined structures can be applied to components due to interference (that is a periodic modulation of laser intensity) resulting from superposition. Fraunhofer IWS scientists are able to fabricate constant structure geometries on large areas at rates of up to nearly 1 m2 min-1 by means of the DLIP technology. However, the generation of variable structure geometries at high process speeds makes it necessary to develop advanced solutions.
The Fraunhofer IWS has succeeded for the first time in developing a structuring procedure able to fabricate these variable structures in short process times. The solution arises from combining a DLIP processing head with a galvanometer scanner. The system allows for a generation of micrometer structure in a range between 2 µm and 5 µm in an almost infinite manner. Examples include product protection holograms patterned on-the-fly directly on the surfaces of metals, polymers, ceramics and coatings.
The DLIP galvanometer scanning system enables a significant multiplication of the process speed due to the low inertia. Clearly shorter process times, higher flexibilities and thus significant gains of competitiveness are the defined advantages of this development, according to Fraunhofer IWS.