Optimizing micro-grooved biphilic surfaces for enhanced condensation heat transfer and coalescence-induced droplet jumping

Condensation on heat transfer surfaces plays a crucial role in various industrial and energy applications, such as power generation, water harvesting, and thermal management systems. However, condensed droplets, an inevitable by-product of condensation, lead to local deterioration of condensation performance on heat transfer surfaces due to their inherently high thermal resistance. To mitigate this issue, advanced surfaces featuring micro/nanostructures, such as micro-grooved and biphilic surfaces, have been introduced to enhance droplet removal capacity and effective condensation area, thus improving condensation performance. Despite these advances, their practical applications are limited by suboptimal costs, performance, and durability. In this study, we developed a novel micro-grooved biphilic surface that synergistically combines surface modification technologies previously employed on micro-grooved surfaces and biphilic surfaces through cost-effective fabrication processes. Through optimizing the distribution of hydrophilic sites and the dimension of micro-grooves, we have successfully developed a micro-grooved biphilic surface that exhibits significantly enhanced condensation performance and durability. The performance of droplet jumping height on micro-grooved biphilic surfaces was comparable to those on smooth biphilic surfaces. Condensation and durability experiments demonstrated that the optimized micro-grooved biphilic surface, compared to its smooth counterpart, achieved significant enhancements: ∼ 65.1 % in heat flux, ∼ 42 % in water collection flux, and ∼ 25.3 % in durability performance. These substantial improvements in cost saving, condensation performance, and durability demonstrate the practical potential of micro-grooved biphilic surfaces, paving the way for their integration into next-generation heat transfer systems and inspiring future research in advanced surface engineering for condensation enhancement. © 2025 Elsevier Ltd