The synergistic effect of honeycomb structure and substrate thermal conductivity on the reduction of contact time at high temperatures

Rapid detachment of droplets at different temperatures has been extensively studied in recent years by regulating surface wettability or introducing well-designed topological structures. It is of practical significance in many industrial fields such as dropwise condensation, self-cleaning, and so on. However, a single material cannot satisfy a wide range of applications. The synergistic effect of surface structure and substrate thermal conductivity on the regulation of contact time at high temperatures has not been revealed. In this work, we prepare hierarchically non-interconnected honeycomb surfaces with four different substrates and explore droplet dynamics at different temperatures. The unique pancake bouncing can be observed on the honeycomb surface and the solid-liquid contact time is largely shortened, which is aroused by the generation of strong vapor pressure in the non-interconnected structure. We also discover that both the increase in temperature and substrate thermal conductivity can reduce the contact time of droplets on the honeycomb surface. Therefore, we speculate that droplet dynamics at high temperatures can be modulated through the rational use of substrate materials and topological structure, which may find wide applications in thermal-related fields, such as high-frequency spray cooling.