Berkeley Fluids Seminar
University of California, Berkeley
Bring your lunch and enjoy learning about fluids!
December 4, 2013
Prof. Peichun Amy Tsai (University of Twente, The Netherlands)
Controlling Splashing and Slippage on Superhydrophobic Surfaces
In this talk, I will demonstrate how to modify surfaces to alter bulk flow using hydrophobic micro-structures. The wax-like micro-textures display superhydrophobicity, yielding a large static contact angle of water droplet with a low contact angle hysteresis. Two dynamical scenarios: drop impact and laminar flow on superhydrophobic surface, will be presented. At a high impact velocity splashing of water droplet can occur, emitting secondary droplets. Moreover, the splashing dynamics is strongly influenced by the micro-patterns of the substrate. In microfluidic laminar flow, the geometry of the liquid-gas interface affects slippage, i.e. drag reduction, using hydrophobic micro-structures. We found that air and air flow play an important role in these two scenarios, revealing the importance of developing an active control of the gas-liquid interface at the flow boundary.