Turning Theory into Practice: Robust Hierarchical Biomimetic Composites by Design using Direct Write Assembly and Biomineralization-Inspired Interfaces

金属和塑料等传统工程材料通常以韧性换取强度。这对于既需要强度又需要韧性的苛刻工程应用来说是一个挑战。天然复合生物材料，如骨、鹿角和珍珠层，是追求高性能和耐用材料的灵感来源，因为它们坚硬、坚固和坚韧。与金属相比，它们在“强度与重量比”方面也具有竞争力。理论建模提供了实现其理想特性所需的组成和多尺度结构的洞察力。最近的研究为合成层次化仿生复合材料带来了潜在的“设计指南”。但这些设计指导方针能被应用吗？这是本提案中解决的基本工程挑战。利用冷冻铸造技术制备出了力学性能可与某些金属合金媲美的珍珠层状仿生复合材料，但该工艺缺乏适应性和通用性。添加剂制造可以克服这些限制。*拟议研究计划的目标是生产和测试分层、多尺度的仿生复合材料，并随后为其设计启用新的、颠覆性的技术，在不同的工程领域的生产和应用。*两个具体目标是：*a)使用传统和广为人知的工程聚合物系统，结合商业上可获得的无机颗粒和新型界面偶联剂，方便地测试和验证层级生物力学衍生的“设计指南”。*b)开发“按设计”方法生产高度模仿但机械性能优于皮质骨的仿生复合材料。*将使用直接写入组装来生产新型的“设计的”仿生复合材料。通过对新型油墨的精确挤出，可以打印出直径约为100微米的细丝。复合材料将以逐层方式组装。复合材料的结构将使用最先进的方法进行表征和测试。结构和力学性能将与《设计指南》模型预测和模型材料进行比较。这是一种自下而上的“按设计”的方法。*人们普遍认为，如果能够高效和有效地生产，合成仿生复合材料将有可能给许多工程领域带来革命性的变化，因为它们被预测为具有优异的机械性能。这项研究计划将开启一条实用和适应性强的设计和生产耐用、高性能仿生复合材料的道路。随着我们未来从自然资源基地转向知识/创新基地，这种创新将有助于推动加拿大经济。在该计划的5年中，将培训10名HQP。*

Conventional engineering materials, like metals and plastics, typically trade toughness for strength. This represents a challenge in demanding engineering applications where both strength and toughness are required. Natural composite biomaterials like bone, antler, and nacre serve as inspiration in the pursuit of high performance and durable materials because they are stiff, strong and tough. They also compete with metals when compared in terms of “strength to weight ratios”. Theoretical modeling has provided insights into the composition and multi-scale structure required to achieve their desirable properties. Recent studies have resulted in potential “design guidelines” for synthetic hierarchical biomimetic composites. But can these design guidelines be applied? This is the fundamental engineering challenge addressed in this proposal. A nacre-like biomimetic composite with remarkable mechanical properties comparable to some metal alloys has been produced using freeze casting but the process lacks adaptability and versatility. Additive manufacturing can overcome these limitations.***The Objective of the proposed research program is to produce and test hierarchical, multi-scale biomimetic composites and to subsequently enable novel, disruptive technologies for their design, production and application in various fields of engineering.***Two specific objectives are:***A) Expedient testing and verification of hierarchical biomechanics-derived “design guidelines” using conventional and well-understood engineering polymer systems combined with commercially available inorganic particles and novel interface coupling agents.***B) Development of “by design” approaches for production of biomimetic composites that highly mimic but mechanically outperform cortical bone.******Novel “designed” biomimetic composites will be produced using direct write assembly. By the precise extrusion of novel inks, filaments on the order of 100 microns in diameter will be printed. Composites will be assembled in a layer by layer fashion. The structures of the composites will be characterized and tested using state-of-the-art methods. The structure and mechanical behaviour will be compared to the “design guideline” model predictions and model materials. This is a bottom-up, “by design” approach.***It is broadly agreed that synthetic biomimetic composite materials have the potential to revolutionize many fields of engineering due to their predicted superior mechanical properties if they can be produced efficiently and effectively. This research program will initiate a path to the practical and adaptable design and production of durable, high performance biomimetic composite materials. Such innovation will help drive Canada's economy as we shift from a natural resource base to a knowledge/innovation base in the future. Ten HQP will be trained during the 5 years of the program.***********