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

传统的工程材料，如金属和塑料，通常以韧性换取强度。这在要求强度和韧性都很高的工程应用中是一个挑战。天然复合生物材料，如骨头、鹿角和珍珠，是追求高性能和耐用材料的灵感来源，因为它们坚硬、坚固、坚韧。在“强度与重量比”方面，它们也与金属竞争。理论建模为实现其理想性能所需的成分和多尺度结构提供了见解。最近的研究已经为合成层次仿生复合材料提供了潜在的“设计指南”。但是，这些设计准则能够应用吗？这是本提案所要解决的基本工程挑战。利用冷冻铸造技术制备了一种具有与某些金属合金相当的优异力学性能的类珍珠仿生复合材料，但该工艺缺乏适应性和通用性。增材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，多尺度仿生复合材料，并随后为其设计，生产和应用于各种工程领域提供新颖，颠覆性的技术。***两个具体目标是：***A)使用传统的和众所周知的工程聚合物系统结合商用无机颗粒和新型界面偶联剂，对分层生物力学衍生的“设计指南”进行权宜测试和验证。***B)开发“通过设计”的方法来生产高度模仿但机械性能优于皮质骨的仿生复合材料。******新颖的“设计”仿生复合材料将使用直接写入组装生产。通过新型油墨的精确挤压，将打印出直径约为100微米的细丝。复合材料将以一层一层的方式组装。复合材料的结构将采用最先进的方法进行表征和测试。结构和力学行为将与“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“设计”方法。***人们普遍认为，合成仿生复合材料有可能彻底改变许多工程领域，因为他们可以预测的优越的机械性能，如果他们可以高效和有效地生产。这一研究项目将为设计和生产耐用、高性能的仿生复合材料开辟一条实用、适应性强的道路。随着加拿大未来从自然资源基地向知识/创新基地的转变，这些创新将有助于推动加拿大经济的发展。10名HQP将在5年的项目中接受培训。***********

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.***********