冷凝微滴自驱动微纳多级结构的超快激光定向电结晶复合制造技术研究

高效相变热控系统是满足小面积、大热流密度散热、均热需要的最佳解决方案。凝结过程是工质相变的核心过程，直接决定了相变热控系统的整体换热能力。具有微纳复合结构的超疏水表面在前期研究中展现出了极佳的滴状凝结潜力，可以成倍提高凝结过程的热效率。但是现有方法制造的表面微结构对冷凝液滴的驱动力不强，无法在高蒸汽饱和度下维持滴状凝结。.基于前期实验和理论探索，本项目拟设计和制造一种具有冷凝微滴自驱动特性的微纳多级结构，增强表面结构对冷凝液滴的驱动力，获得持续的超细滴状凝结过程。本项目围绕微纳尺度结构对多尺度冷凝液滴的迁移与融合行为的影响机制、超快激光诱导表面形貌/缺陷/成分对定向电结晶形核生长/液相传质等过程的影响机制等关键科学问题，深入研究锥状微纳多级结构的复合制造方法，及这种微观表面的凝结与液滴迁移行为。项目成果可以为新一代高效相变热控器件寻求新的思路和技术解决方案，具有重要的科学和应用价值。

High-performance phase transition thermal control system is the best solution for the thermal dissipation and homogenization of situations with small area and high heat flux density. Condensation is the key process in phase transition, and decides the overall heat transfer capacity of phase transition thermal control system directly. Superhydrophobic surfaces with hierarchical micro/nano structures show excellent potential of dropwise condensation in previous studies, which can greatly enhance the heat transfer efficiency of condensation. However, the driving force to condensate droplets of present microstructures is not high enough to maintain the dropwise condensation under high vapor saturation.. Based on our preliminary experiment and theoretical exploration, this project is intended to design and manufacture a kind of multilevel micro/nano structures with the self-propelling property to condensate micro-drops, which can enhance the driving force to condensate droplets and achieve continuous dropwise condensation. The key scientific problems in this project are the influencing mechanism of surface micro/nano structures to the migration and coalesce of condensate droplets, and the influencing mechanism of ultrafast laser-induced surface morphology, defects and composition to the nucleation and growth of crystallization and liquid mass transfer during the directional electro-crystallization. Starting with these basic scientific problems, this project will in-depth study the fabrication method of cone-shaped multilevel micro/nano structures, and the condensation and droplet migration on these microstructures. The project outcome can provide new ideas and solutions for the development of the new generation phase transition thermal control system, and have both values in science and industry.