Femtosecond Laser Direct Writing of Porous Network Microstructures for Fabricating Super-Slippery Surfaces with Excellent Liquid Repellence and Anti-Cell Proliferation

In this paper, it is demonstrated that one-step femtosecond laser ablation can be used to directly fabricate porous network microstructures on various polymer surfaces, including poly(ethylene terephthalate) (PET), poly(methyl methacrylate), polyamide, polycarbonate, polyethylene, and polylactic acid. Taking PET as an example, following femtosecond laser ablation, the PET surface is fully covered by large numbers of interconnected pores with a diameter of several hundred nanometers. The chemical treatment of the porous surface for further lowering of its surface free energy and infusion with lubricating liquid led to the successful fabrication of a slippery surface. The as-synthesized slippery surface showed excellent liquid-repellent ability; various liquids are demonstrated to freely slide down such a surface. Compared to previously reported slippery surfaces, the femtosecond laser-induced slippery surface consists of a porous layer and substrate layer that are inherently one material. Furthermore, it is found that the use of the original laser-induced porous PET surface as a culture substrate is able to promote the growth of C6 glioma cells, while the slippery PET surface completely inhibits C6 glioma cell growth. It is revealed that femtosecond laser direct writing can be used as a general method to form porous microstructures on various polymer surfaces.