Wettability of Femtosecond Laser Direct Fabrication of Micro and Nanostructures on Metal Surface

Abstract

In this article, we focused the femtosecond laser pulse on the nickel surface and scan with a pitch smaller than the size of focused beam size. After a homogeneous laser irradiation on the surface, a cylindrical two-scale micro/nano composite structure was prepared. We found that the wettability of micro-nanostructure surface does not spontaneously change from hydrophilicity to hydrophobicity in air, which is different from the result of micro/nanostructured surface prepared on steel, titanium alloy and pure coppersurfaces by femtosecond laser. The results ofthis article show that the contact angle of micro /nano structuredsurface can reach up to 148.28^o after silanization near to superhydrophobicity. This discovery is of significant importancefor the selection of the base materials for the preparation of metal wettability surface bymicro/nanostructures.