Evaporation heat transfer enhancement by a laser-textured heterogeneous surface

Numerous studies have explored the influence of surface wettability on liquid vapor heat transfer through surface modification; especially when the surface can be modified with heterogeneous wettability. Herein the heterogeneous wettability surfaces with the designated patterns can be created on surfaces only in a few seconds after laser irradiation. LSCM images indicated the surfaces with laser irradiation became rougher and provided more nucleation sites. In this study, experiments for evaporation behaviors of water droplet were performed on picosecond laser-textured heterogeneous copper surfaces. The CCD images revealed that bubble dynamics play an important role in droplet evaporation on heated surfaces. Based on the behavior of bubble coalescence and departure, the heterogeneous laser-textured surface exhibited superior evaporation efficiency.