Modelling of femtosecond laser-induced periodic surface structures and its application in fabricating corrosion-resistant superhydrophobic surface

Laser-induced periodic surface structures (LIPSS) enable functional surface engineering with tailored properties for diverse applications in optics, biomedicine, and industrial technologies. An analytical model based on fluence-dependent transient electron excitation and surface plasmon polariton theory is developed to establish a physics-based relationship between laser processing parameters and LIPSS periodicity. The crucial laser fluence ( F M ) needed for LIPSS creation was identified through femtosecond laser processing studies, and it was discovered to be dependent on scanning speed and laser power. The experimental findings verified the analytical model’s accuracy and showed that F M rises as scanning speed increases. According to the proposed model, both the laser wavelength and fluence are positively correlated with the LIPSS period within a specific range. Furthermore, by affecting the laser fluence, variables like scanning speed, hatch spacing, laser power, and repetition rate can indirectly modify the LIPSS duration. Femtosecond laser processing, guided by the LIPSS model, was utilized to successfully create a superhydrophobic surface on 316 L stainless steel with exceptional corrosion resistance, attaining a contact angle of up to 162.4°.