Novel High-Performance Bio-inspired Architectured Materials

混合材料结合了至少两种具有不同性质的成分，这些成分相互补充并导致有吸引力的性质组合。混合材料分为(i)纤维和颗粒复合材料，（ii）三明治，（iii）晶格和（iv）分段混合材料（也称为建筑材料）。虽然前三种类型的混合材料现在已经达到技术成熟，但建筑材料在很大程度上仍未得到充分开发。这些不寻常的材料是由尺寸和形状明确的建筑块组成的，排列成二维或三维。有趣的是，骨、牙齿和软体动物等天然材料表明，尽管材料结构薄弱，但材料结构可以产生非常高的结构性能。用积木制作材料的概念也特别适合自下而上的制造、可持续性、材料修复和多功能。在这项工作中，我们将优化材料结构的刚度，硬度和韧性，这是在单片材料中难以同时实现的性能。刚度和硬度将由构建块提供，而韧性将由界面上受控的失效机制提供。例如，在机械应力裂缝下，建筑块将被设计成滑动、旋转、分离或联锁，产生独特的变形和破坏机制，从而产生吸引人的宏观特性。该计划的具体目标是：(i)建立一般设计准则，以实现建筑材料的刚度，强度和韧性的有吸引力的组合；（ii）定制建筑模块之间的界面，使它们提供凝聚力，韧性和能量耗散；（iii）探索建筑材料的成本和能源效率制造途径。我们将通过结构建模和优化、界面力学、断裂测试以及包括自组装和激光雕刻在内的创新制造方法来实现这些目标。该创新项目将招收4名博士生和1名硕士生，预计将在材料科学领域做出原创性的科学贡献。

Hybrid materials combine at least two components with distinct properties which complement each other and lead to attractive combinations of properties. Hybrid materials are categorized into (i) fiber and particulate composites, (ii) sandwich, (iii) lattice and (iv) segmented hybrids (also called architectured materials). While the first three types of hybrid materials are now reaching technological maturity, architectured materials remains largely underexplored. These unusual materials are made of building blocks of well defined size and shape, arranged in two or three dimensions. Interestingly, natural materials such as bone, teeth and mollusk demonstrate how material architecture can lead to remarkably high structural performance properties despite of weak building blocks. The concept of making materials from building blocks is also particularly well-suited to bottom-up fabrication, sustainability, material repair and multi-functionalities. In this work we will optimize material architectures for stiffness, hardness and toughness, which are properties that are difficult to achieve simultaneously in monolithic materials. Stiffness and hardness will be provided by the building blocks, while toughness will be provided by controlled failure mechanisms at the interfaces. For example, under mechanical stress cracks the building blocks will be designed to slide, rotate, separate or interlock collectively, generating unique deformation and failure mechanisms leading to attractive macroscale properties. The specific objectives of this program are to (i) establish general design guidelines to achieve attractive combinations of stiffness, strength and toughness in architectured materials; (ii) tailor the interfaces between the building blocks so they provide cohesion, toughness and energy dissipation and (iii) explore pathways to cost- and energy-effective fabrication of architectured materials. We will achieve these goals through structural modeling and optimization, interface mechanics, fracture testing and innovative fabrication approaches including self-assembly and laser engraving. This innovative program will involve four PhD students and one Masters student, and is expected to make original scientific contributions to the field of materials science.