Manufacturing of Super-Repellent Surfaces with High Mechanical Resilience

模拟荷叶并具有超强驱避性的表面有许多应用，包括减阻、防冰、传热和防生物污垢。然而，大多数目前可制造的表面对不够广泛的流体范围都是排斥的，并且缺乏机械耐用性。为了增强它们的拒液性，可以在表面结构中加入纳米级的悬垂部分。然而，悬挑类似于机械上薄弱的倒金字塔形状，使得这些表面更容易受到日常机械压力的破坏，例如被人的手指触摸。该项目旨在解决这一根本冲突，并为一种新型的超级排斥表面铺平道路，这种表面结合了通用的液体排斥和机械弹性，到目前为止，由于它们的几何要求不同，这两种表面一直被认为是相互排斥的。这项研究将集中于开发一种新的设计和制造方法，以增强排斥表面的机械坚固性，使其对各种机械载荷具有弹性，如折叠和锤击。这项研究的结果可能会对以前因机械脆弱性而受阻的广泛现实世界应用产生重大影响。这个跨学科的项目包括纳米制造、材料科学、微流体学和界面科学。它还包括让本科生和高中生参与协作研究任务，以促进包容性并提供动手STEM培训，包括针对该领域传统上代表性不足的群体。与主要依赖牺牲一小部分顶层表面结构以延缓排斥损失的现有解决方案不同，这种制造方法将使用软材料和刚性材料的组合来创建混合表面结构。这一创新防止了表面结构被破坏，因为当受到机械载荷时，混合表面结构变形成软衬底，随后在载荷被移除后恢复其原始形状。因此，可以保持这些杂化表面结构上的超强排斥性。本项目旨在研究混合表面结构的力学耐久性，并分析材料变化和细节几何对其设计的影响。因此，它将为制造具有高机械弹性的超级排斥表面提供基本的见解和工程指导方针。这项研究调和了强防液面的形状要求和机械坚固性之间的内在冲突，有望克服超疏水表面实际应用的科学障碍。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Surfaces that mimic lotus leaves and have super-repellent properties have numerous applications, including drag reduction, anti-icing, heat transfer, and anti-biofouling. However, most presently-manufacturable surfaces are repellent to an insufficiently-broad range of fluids and lack mechanical durability. To enhance their liquid repellency, nanoscale overhangs in the surface structures can be incorporated. However, overhangs resemble an inverted pyramid shape that is mechanically weak, making these surfaces even more prone to damage from everyday mechanical stresses, such as being touched by human fingers. This project aims to address this fundamental conflict and pave the way for a new type of super-repellent surface that combines universal liquid repellency and mechanical resilience, which have so far been believed to be mutually exclusive due to their contrasting geometric requirements. The research will focus on developing a novel design and manufacturing method to enhance the mechanical robustness of repellent surfaces, making them resilient to various mechanical loads, such as folding and hammering. The outcomes of this research could have significant implications for a wide range of real-world applications that were previously hindered by mechanical fragility. This interdisciplinary project encompasses nanomanufacturing, material science, microfluidics, and interfacial science. It also includes initiatives to engage undergraduate and high school students in collaborative research tasks to foster inclusivity and provide hands-on STEM training, including for groups that have traditionally been underrepresented in the field.Unlike existing solutions that primarily rely on sacrificing a fraction of the top surface structures to delay the loss of repellency, this manufacturing method will use a combination of soft and rigid materials to create hybrid surface structures. This innovation prevents the surface structures from being damaged, because when subjected to mechanical loads, the hybrid surface structures deform into the soft substrate and subsequently recover their original shapes once the load is removed. Consequently, the super repellency on these hybrid surface structures can be maintained. This project aims to study the mechanical durability of hybrid surface structures and analyze the impact of material variations and detailed geometries on their design. It will thus yield fundamental insights and engineering guidelines for manufacturing super-repellent surfaces with high mechanical resilience. By reconciling the inherent conflict between the shape requirements for strong liquid repellency and mechanical robustness, this study is expected to overcome a scientific barrier to the practical utilization of super-repellent surfaces.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.