Roughness structures in the micro- and nano-ranges play a key role for functional surfaces. Ultra-hydrophobic, hydrophilic, and anti-fog properties can be achieved by a variety of stochastic but deliberately tailored roughness characteristics. This results in promising potential for the fabrication of such structures. Moreover, it even allows for linking the functional properties with optical quality (e.g. for glass surfaces). At the same time, novel challenges arise for appropriate characterization methods as well as simulation and modelling techniques.
With the flexible modeling, measurement and analysis tools developed at Fraunhofer IOF, we are capable of predicting, defining and controlling roughness structures for optimal hydrophobic and hydrophilic properties. The direct link of simulation, fabrication, and characterization constitutes a unique basis for efficiently triggering the entire process chain.
Sol-gel coatings from ETC PRODUCTS GmbH with adjustable nano roughness enable the fabrication of both ultrahydrophobic (advancing contact angle: 155°, hysteresis < 30°) and hydrophilic, anti-fog glass surfaces. At the same time, scattering losses are minimized.