Strategies for Micropatterned, Nanopatterned, and Hierarchically Structured Lotus-like Surfaces

It has been demonstrated experimentally that roughnessRoughness changes contact angleContact angle (CA) in accordance with the WenzelWenzel model or the Cassie-BaxterCassie-baxter model, depending upon whether the surface is hydrophilicHydrophilic or hydrophobicHydrophobic (Bhushan and Jung 2011). Yost et al. (1995) found that roughnessRoughness enhances wettingWetting of a copper surface with Sn–Pb eutectic solder, which has a contact angleContact angle of 15°–20° for a smooth surface.