CAREER: Directed Epitaxial Assembly of Structural Biopolymers in Hierarchical Mesostructures for Enhanced Mechanical Behavior, Mass Transport and Heat Transfer

这一学院早期职业发展计划(CALEAR)奖支持基础研究，使活的有机体掌握的新纳米制造范例能够将中尺度(50-500纳米)的分层组织赋予纳米结构材料。目前的纳米制造过程涉及复杂的耗时和耗能的步骤，需要对组装环境进行严格的监管，并且通常不允许跨长度尺度(从纳米到宏观)的分层组织。这个项目研究的是定向外延组装，这种组装能够使用类生命丝素的构建块高效地制造分层介观结构材料。这种能力允许集成三维材料的介观特征，并制造具有增强的机械、热传输和质量传输特性的多功能材料。事实上，分层介观结构材料是一类新的材料，在下一代高科技材料的设计中具有越来越重要的作用。此外，对天然聚合物中纳米级组装现象的基本理解将生物体的制造规则与技术联系在一起。该项目的成果有可能极大地影响国家经济和公共福利，并在NSF关于人类技术前沿工作的未来和理解生活规则的大想法中产生分支。此外，这项研究的跨学科性质，涉及纳米制造、材料科学、蛋白质工程、热力学和生物化学，有助于扩大年轻科学家和未被充分代表的群体对研究的参与，并对工程学教育产生积极影响。这一职业项目的目标是了解和利用作用力和场的协调，使能够在分级介观结构材料中纳米制造结构生物聚合物，模拟在活体中发生的过程。这一基本理解定义了一种新的纳米制造范式，能够在中尺度上形成复杂的体系结构。这一愿景的主要障碍是对调节生物聚合物组装的现象缺乏了解，以及缺乏在复杂系统中混合自下而上和自上而下方法的制造技术。在这项研究中，热力学原理、定向组装、添加剂制造和蛋白质工程为探索和利用结构蛋白折叠、组装和融合提供了基本工具。特别是，利用连接多肽的序列-结构-组装属性的设计原则在纳米尺度上研究结构蛋白(例如丝素)的外延生长，并允许将其用作种子材料以模板和直接组装过程。这一基本认识使基于生物聚合物的分级介观结构材料的纳米制造成为可能，目前的纳米制造技术无法实现这种材料，这些材料表现出增强的韧性和弹性、选择性的质量传输和模块化的散热，影响到横跨生物医学、农业、航空航天、汽车、微电子和能源应用的几个技术领域。该奖项反映了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。

This Faculty Early Career Development Program (CAREER) award supports basic research that enables a new nanomanufacturing paradigm, which has been mastered by living organisms, to impart hierarchical organization at the mesoscale (50-500 nanometers) to nanostructured materials. Current nanomanufacturing processes involve complex time- and energy-consuming steps, require meticulous regulation of the assembly environment, and, generally do not allow hierarchical organization across length-scales (from nano to macro). This project investigates directed epitaxial assembly that enables the efficient fabrication of hierarchical mesostructured materials using the building blocks of life -- like silk. Such a capability allows integration of mesoscaled features in three-dimensional materials and the manufacture of multifunctional materials with enhanced mechanical, heat transfer and mass transport properties. Hierarchical mesostructured materials are, in fact, a new class of materials with increasing importance in the design of the next generation of high tech materials. Additionally, the basic understanding nanoscale assembly phenomena in natural polymers liaises the rules of fabrication in living matter with technology. The outcomes of this project have the potential to greatly impact national economy and general welfare, with ramification in the NSF's Big Ideas of the Future of Work at the Human-Technology Frontier and Understanding the Rules of Life. Furthermore, the interdisciplinary nature of the study, which involves nanomanufacturing, material science, protein engineering, thermodynamics and biochemistry, helps broaden participation of young scientists and underrepresented groups in research and positively impact engineering education.The objective of this CAREER project is to understand and exploit the orchestration of forces and fields that enable the nanomanufacturing of structural biopolymers in hierarchical mesostructured materials, mimicking processes that occur in living organisms. This basic understanding defines a new nanomanufacturing paradigm that enables the formation of complex architectures at the mesoscale. The major barriers to this vision are a poor understanding of the phenomena that modulate biopolymer assembly and the lack of fabrication techniques that blend bottom-up and top-down approaches in complex systems. In this study, thermodynamic principles, directed assembly, additive manufacturing and protein engineering provide the basic tools to explore and harness structural proteins folding, assembly and fusion. In particular, epitaxial growth of structural proteins, e.g., silk, is studied at the nanoscale using design principles that liaise the sequence-structure-assembly properties of polypeptides and that allow for their use as seed materials to template and direct assembly processes. This basic understanding enables the nanomanufacturing of biopolymer-based hierarchical mesostructured materials, unattainable with current nanomanufacturing techniques, that exhibit enhanced toughness and resilience, selective mass transport and modular heat dissipation, impacting several technological fields that span biomedical, agriculture, aerospace, automotive, microelectronics and energy applications.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.