Research progress in the construction of anisotropic micro-/nano hierarchical structural materials with unique wetting behavior

Many natural biological anisotropic wetting surfaces showed a typical directional difference in the wetting behavior for manipulating water droplets. In recent years, the fabrication of micro-/nano- hierarchical structural materials with directional differences has attracted a widely research interest. Drawn inspirations from nature, building anisotropic structural surface is the key to realize the directional wetting behavior. Herein, the research progresses in fabricating anisotropic micro-/nano hierarchical structural materials, as well as the typical directional wetting behavior on their surfaces with different topological nature are summarized. It will be helpful for promising applications in various fields as microfluidic devices, water/oil separation and high efficient liquid collection and so on.