Condensation Optimization on Biphilic Patterned Surfaces

Dropwise condensation plays a large role in heat transfer, both in nature and in industry. Other experiments have explored ideas regarding altering surface characteristics to change effectiveness on condensation. However, due to the complex surface-droplet interactions, condensed droplets continue to coalesce randomly across a substrate. Droplets must reach a certain size before gravitational effects have enough force to strip the droplets from the surface. Hence, heat transfer and condensation are still inhibited by condensation areas that inhabit un-shed droplets. In order to circumvent these obstacles, we propose patterned microstructures on the condensation surface to order the condensation and coalescence. Through optical imaging, we show the improved effect on condensation of patterned aluminum surfaces with biphilic coatings, to promote drop shedding events leading to more efficient heat transfer through condensation. Our work provides framework to predict and improve both condensation and drop shedding on patterned surfaces.