One-step fabrication of asymmetric saw-tooth-like surface structures on stainless steel using direct laser interference patterning

We report about the fabrication of asymmetrical periodic arrays on stainless steel by means of Direct Laser Interference Patterning. The fabrication strategy consists in irradiating the surface of the material under a certain inclination angle using a two-beam interference setup equipped with a pulsed picosecond laser system (70 ps) operating at a wavelength of 1064 nm. In particular, for tilting angles higher than 30°, well-defined saw-tooth like geometries could be produced. Due to the ultra-short duration of the laser pulses, also Laser Induced Periodic Surfaces Structures are fabricated, which create hierarchical morphologies similar to the one present in nature.