Effect of Microstructure on Liquid Infused Surfaces during Condensation Phase Change*

Liquid infused surfaces (LIS) have received increasing attention for their extremely low contact angle hysteresis and excellent droplet mobility, which makes them potential candidates for anti-icing and heat transfer purposes. The excellent low adhesion of LISs is owed to the presence of a lubricant/oil that decreases further the intimate direct interactions between the solid surface ant the condensate. Although the effect of micropillar structure on droplet mobility after sessile drop deposition has been extensively addressed, the presence or absence of microstructures during dynamic condensation  has not been reported up to date. Two different micro-/nano-structured LISs and two nano-structured LIS were fabricated following facile-scalable etching and oxidation techniques. The density and size of the micro-structures was found to differ depending on the etching time. All four LISs were subjected to condensation on an environmental chamber. Here, ewwe present first experimental evidences and surface energy analysis to demonstrate and support the greater shedding velocities and condensation performance of micro-/nano-structured LISs when compared to solely nano-structured LISs.