Applied Surface Science, Vol.481, 184-191, 2019
Controllable drop splashing on picosecond laser patterned hybrid superhydrophobic/-philic surfaces
Drop splashing is a very common phenomenon when liquid drops impact on solid surfaces. In this study, picosecond laser fabricated hybrid superhydrophobic/-philic (SH/SHL) surfaces with designed patterns are successfully applied to control drop splashing on solid surfaces. Using high-speed imaging, the water drop impact behaviors on differently patterned hybrid SH/SHL surfaces were investigated. The experimental results show that the water drop splashing could be restrained greatly on patterned hybrid SH/SHL surfaces, compared with SH or SHL surfaces. On a hybrid SH/SHL surface with a 2 mm diameter circular SH pattern, the drop splashing for a Weber number up to 600 (the corresponding impact velocity is 4.2 m/s) can be totally suppressed. Moreover, we found that the oriented distribution of splashing can be regulated by the shape and size of SH patterns. These results suggest that patterned hybrid SH/SHL surfaces could be a practical approach to regulate or control drop splashing.