Superhydrophilic properties driven by highly-regular laser-induced periodic structures on Si surface

In this work an investigation about the effects of high-speed, highly-regular laser induced periodic surface structures (HR-LIPSS) on wetting properties of silicon surface are presented and discussed. In order to investigate the influence of chemistry on wetting properties of textured surfaces, treatments were performed both under air and N2 shielding gas. The morphology was investigated by Scanning Electron Microscope (SEM), the chemistry by energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy and the wetting properties by camera recording. The results demonstrate substantial effects of HR-LIPSS on wetting properties of silicon surface. The hydrophilic Si surface becomes superhydrophilic after femtosecond nanopatterning and the addition of N2 in laser treated zone essentially influences the chemistry of the surface, this permits to control the water flowing and makes HR-LIPSS more flexible, bringing up to a new level of control of wettability properties for several applications.