天然生物材料具有精巧的多尺度分级结构、优异的综合性能、高效的生物功能，对于其粘附、浸润、摩擦、强度、韧性等性质，表面与界面都起着至关重要的作用。本项目将通过实验测量、理论分析和数值模拟，研究天然生物材料表面和界面的变形与失效的三种典型形式——形貌失稳、表面磨损和界面开裂，以期深入认识其“化学成分－几何结构－力学性质－生物功能”之间的内在关系。发展相应的理论分析模型、数值计算方法和实验测试技术，用以揭示天然生物材料在优异性能中所隐藏的关键物理机制；探究多尺度分级结构、尺度效应、力学－化学－生物学耦合特性等因素对其表面与界面力学行为的影响规律；利用实验测量、损伤和断裂力学方法，分析不同种类复合材料在损伤模式、强韧化机制等方面的异同；将压痕、吸管等方法推广应用于生物软材料的超弹性、粘弹性等本构参数的实验测量；并探索研究结果在复合材料界面强韧化、表面形貌调控、抗摩擦磨损性能设计等方面的仿生应用。

Almost all biological materials have elegant hierarchical structures, which render them outstanding comprehensive properties and efficient biological functions. For these natural materials, surfaces and interfaces often play a critical role in determining their physical properties, e.g., adhesion, wetting, friction, mechanical strength and toughness. In this project, systematic experimental measurements, theoretical analyses and numerical simulations will be carried out to study three typical deformation and failure modes of surface and interfaces, including morphological instability, surface wear, and interfacial cracking. The outcome of this study will help better understand the intrinsic relationship among their chemical compositions, geometrical structures, mechanical properties, and biological functions. More specifically, we will develop some relevant theoretical and experimental techniques to reveal the key physical mechanisms underlying the exceptional properties of biological materials. The influences of hierarchical structures, length-scale effects, mechanical–chemical–biological coupling on the behavior of surfaces and interfaces will be explored. Based on experimental measurements and fracture and damage mechanics analysis, we will interrogate different damage and toughening mechanisms in biological materials. The traditional indentation and aspiration techniques will be developed to characterize the hyperelastic and viscoelastic constitutive relations of typical biological soft materials. Furthermore, we will explore potential biomimetic applications in such fields as interface toughening of composite materials, fabrication and control of surface micro-/nanopatterns, and design of wear-resistant surfaces.