Fabrication of superhydrophobic hierarchical textures on aluminum by combining laser-based methods

摘要

Laser-microtextured surfaces have gained an increasing interest due to their enormous spectrumof applications and industrial scalability. Direct laser interference patterning (DLIP) and the wellestablisheddirect laser writing (DLW) methods are suitable as a powerful combination for the fabricationof multi-scale (DLW+DLIP) textures. In this work, four-beam DLIP and DLW were used combinedto produce functional textures on aluminum. The influence of the laser processing parameters,such as the applied laser fluence and the number of pulses, on the resulting topography was analyzedby confocal microscopy and scanning electron microscopy. The static long-term and dynamic wettabilitycharacteristics of the laser-textured surfaces were determined revealing superhydrophobic propertieswith static contact angles up to 163° and hysteresis as low as 9°. Finally, mechanical stabilitytests revealed that the DLW-patterned craters in the multi-scale texture protect the smaller DLIP featuresunder tribological conditions.