Directional oil sliding surfaces with hierarchical anisotropic groove microstructures.

In general, negative slope structures such as overhang or reentrant shapes have been employed to resist the energetically favorable Wenzel state. More recently, Aizenberg and coworkers demonstrated remarkable slippery surfaces against liquids of low surface tension by exploiting liquid-infused porous structures. [ 9 ] These directional oil sliding surfaces have many potential applications in microfl uidics, mobile market, and oil transportation and semiconductor industry to transport or collect remaing oil effi ciently as well as to prevent contamination from the oil. [ 10–14 ]