The Tuning of LIPSS Wettability during Laser Machining and through Post-Processing

In this work, we investigate the fabrication of stainless-steel substrates decorated with laser-induced periodic surface structures (LIPSS) both hydrophilic and hydrophobic wettability through different post-processing manipulation. carrying out these experiments, have found that while a CO2-rich atmosphere during irradiation does not affect final wettability, residence in such an after indeed increase hydrophobicity. Contrarily, boiling water bath will instead lead to surface. Further, our experiments show importance removing non-sintered nanoparticles agglomerates laser micromachining. If they are removed, demonstrate nanoparticle themselves become hydrophobic, creating Cassie air-trapping layer on which presents contact angles 180°. However, lacks robustness; particles removed contacting water. What is left behind LIPSS integral largely been blocked from reacting surrounding atmosphere. The actual angle approximately 80°. Finally, chemical reactions metallic surfaces only comparatively slower than metals irradiated hierarchical roughness. This shown be important consideration achieve highest degree hydro-philicity/phobicity possible. For example, repeated goniometric measurements over first 30 days following micromachining reduce ultimate 65°, compared 135° when undisturbed for days.