Bioinspired micro/nanostructured surfaces prepared by femtosecond laser direct writing for multi-functional applications

Femtosecond laser direct writing (FLDW) has been widely employed in controllable manufacturing of biomimetic micro/nanostructures due to its specific advantages including high precision, simplicity, and compatibility for diverse materials in comparison with other methods (e.g. ion etching, sol-gel process, chemical vapor deposition, template method, and self-assembly). These biomimetic micro/nanostructured surfaces are of significant interest for academic and industrial research due to their wide range of potential applications, including self-cleaning surfaces, oil-water separation, and fog collection. This review presents the inherent relationship between natural organisms, fabrication methods, micro/nanostructures and their potential applications. Thereafter, we throw a list of current fabrication strategies so as to highlight the advantages of FLDW in manufacturing bioinspired microstructured surfaces. Subsequently, we summarize a variety of typical bioinspired designs (e.g. lotus leaf, pitcher plant, rice leaf, butterfly wings, etc) for diverse multifunctional micro/nanostructures through extreme femtosecond laser processing technology. Based on the principle of interfacial chemistry and geometrical optics, we discuss the potential applications of these functional micro/nanostructures and assess the underlying challenges and opportunities in the extreme fabrication of bioinspired micro/nanostructures by FLDW. This review concludes with a follow up and an outlook of femtosecond laser processing in biomimetic domains.