Superhydrophobic Copper Surfaces By Laser Surface Structuring With Bursts Of Femtosecond Pulses

In this work, Laser Induced Periodic Surface Structures (LIPSS) were generated on copper with bursts of fs laser pulses in the sub-THz regime. The wettability of the textured samples was evaluated by measuring the static water contact angle (WCA) as a function of the burst configuration. A stable superhydrophobic and antiadhesive character without any additional chemical treatment was found when using long bursts (number of pulses within the bursts equal or higher than 16, or intra-burst repetition rate equal or higher than 0.09 THz). Such burst configurations led to the formation of hierarchical structures, consisting of LIPSS decorated by nanoparticles, which enhanced hydrophobic response due to the inherent adsorption of adventitious hydrocarbons.