Turning industrial paints superhydrophobic via femtosecond laser surface hierarchical structuring

The fabrication of functional hierarchical structures on surfaces by laser ablation produces interesting material properties and has attracted considerable research interest. This work addresses the use of laser micro- and nano-machining for the fabrication of modified painted surfaces with controlled wettability. We have identified and optimised surfaces and femtosecond laser conditions to produce hierarchical micro- and nano-scale structures which create effective superhydrophobic painted surfaces for a set of common industrial paints. Roll-off angles as low as 5° were produced, with the ability to remove dirt-like particles down to 50 μm average size. We show how the complex chemical composition of paints plays a crucial role in determining the wettability and self-cleaning properties of painted surfaces following ablation. This work demonstrates the feasibility of this technique, which could be applied to exposed painted industrial surfaces.