Collaborative Research: Biomimetic Nanostructured Materials Based on Synthetic Spider Silk

ID：MPS/DMR/BMAT(7623)1310534 PI：Dzenis，Yuris ORG：内布拉斯加州大学ID：MPS/DMR/BMAT(7623)1310387 PI：Lewis，Randolph ORG：犹他州立大学标题：协作研究：基于合成蜘蛛丝的仿生纳米结构材料技术部分：蜘蛛丝同时表现出优异的强度、硬度和韧性，这是大多数合成结构材料无法实现的壮举。然而，天然丝绸的收获不能达到应用所需的数量。重组丝蛋白非常接近于天然丝素序列，已经在可以进一步放大的过程中合成出来。然而，由这些蛋白质制成的纤维虽然很坚韧，但在重要的强度指标上明显低于天然纤维。近年来，关于各种蛋白质基序对机械性能的影响已经有了很多的研究。尽管许多实验室进行了非常密集的努力，但到目前为止，复制本地纤维纺丝过程导致高度结构的强韧纤维被证明是难以实现的。本项目的目标是开发和研究基于连续丝纳米丝的新型纳米结构合成蜘蛛丝纤维。与其试图通过自组装来复制精致的天然结构过程中难以捉摸的准确条件，不如使用最近优化的自上而下的纳米制造技术来构建仿生分层丝纤维。与来自相同聚合物的固体超细纤维相比，该技术能够生产高度取向和致密的纳米纤维，同时提高强度、弹性和失效时的应变。初步研究表明，从两种不同的合成蜘蛛丝蛋白电纺得到的单个超细纳米纤维具有令人印象深刻的性能。这些性能将通过精密制造的微型纳米纤维得到进一步改善。这些纤维将使用固态核磁共振、傅里叶变换红外光谱和X射线衍射进行分析，以确定影响最佳材料性能的结构元素。这些仿生结构与蜘蛛丝蛋白的原始潜力相结合，可以产生革命性的新纤维，可以工业化生产。人们的期望是开发出超过天然纤维机械性能的人造蜘蛛丝纤维，从而改进自然界最好的结构材料。这项研究将建立在免费的跨学科专业知识和合作伙伴实验室最近的几项突破的基础上。非技术部分：电纺过程的极端灵活性和最近开发的基于复杂的多物理过程建模的精密过程控制方法，为开发新的高性能纳米结构纤维开辟了几乎无限的可能性。这些下一代超强/韧性纤维具有广阔的应用前景。这两个研究小组都有将研究成果商业化的可靠记录，包括用于军事应用的具有纳米纤维增强界面的先进超级复合材料，以及用于肌腱修复材料、体育用品和军事防护材料的蜘蛛丝纤维。这两所大学将建立战略合作伙伴关系，进一步开发独特的超高性能纳米火焰合成蜘蛛丝纤维，并将其商业化。两名不同背景的博士生将相互交流，密切合作。来自两所大学的至少5名本科生也将参与这一研究项目。此外，高级设计项目组将加入这项研究，以测试这些纤维的各种应用。拟议的研究涵盖生物化学、力学、材料科学和纳米制造，并将为学生提供独特的跨学科体验。本科生将在本科生研究日上展示他们的研究成果。这两个实验室都将参与各自大学招收代表性不足群体的努力，特别是为高中生提供实验室参观和亲身实践的努力。作为UNL纳米纤维核心设施的一部分，将开发一种新的纳米结构丝绸设计、制造和表征试验台。该试验台将用于在同事、学生和公众在课堂上频繁访问我们的实验室时进行演示，并用于研究。这一设施试验台还将作为传播新研究成果的工具。这两个群体之前的研究都曾出现在流行媒体以及美国和其他几个国家的几个电视节目中。特别值得注意的是，这项研究在美国国家科学基金会的科学国家计划以及Nova的“制造东西”和探索、历史和迪士尼频道都有特色。两个小组将继续共同推广这项在两所大学进行的令人兴奋的研究。

ID: MPS/DMR/BMAT(7623) 1310534 PI: Dzenis, Yuris ORG: University of NebraskaID: MPS/DMR/BMAT(7623) 1310387 PI: Lewis, Randolph ORG: Utah State UniversityTitle: Collaborative Research: Biomimetic Nanostructured Materials Based on Synthetic Spider SilkTechnical Part: Spider silks exhibit excellent strength, stiffness, and toughness simultaneously, a feat unachievable in most synthetic structural materials. However, natural silks cannot be harvested in quantities necessary for applications. Recombinant silk proteins closely mimicking the natural silk sequences have been synthesized in processes that can be further scaled up. However, fibers made from these proteins, while they are tough, are significantly inferior to natural fibers in the important metrics of strength. Much has been learned in recent years about the effects of various protein motifs on mechanical properties. Despite a very intensive effort in many laboratories, reproduction of the native fiber spinning process resulting in highly structured strong and tough fiber has so far proven elusive. The objective of this project is to develop and study novel nanostructured synthetic spider silk fiber based on continuous silk nanofilaments. Rather than trying to replicate the elusive exact conditions of the delicate native structuring process via self-assembly, biomimetic hierarchical silk fibers will be built using a recently optimized top-down nanomanufacturing technique. The technique is capable of producing highly aligned and dense nanofilamentary fibers with simultaneously improved strength, modulus, and strain at failure, compared to the solid microfibers from the same polymer. Preliminary studies show impressive properties for individual ultrafine nanofibers electrospun from two different synthetic spider silk proteins. These properties will be further improved by precision-manufactured microscopic nanofilamentary fibers. These fibers will be analyzed using solid state NMR, FTIR, and X-ray diffraction to determine the structural elements responsible for the best materials properties. These biomimetic constructs, combined with the original potential of spider silk proteins can lead to revolutionary new fibers that can be produced in industrial quantities. Expectations are to develop synthetic spider silk fibers exceeding the mechanical performance of the natural fibers, thus improving on nature's best structural material. This research will build on the complimentary interdisciplinary expertise and several recent breakthroughs in the laboratories of the co-PIs.Non-Technical Part: The extreme flexibility of the electro-spinning process and recently developed precision methods of process control, based on sophisticated multi-physics process modeling, open up near unlimited possibilities for the development of new high-performance nanostructured fibers. These next generation ultrastrong/tough fibers promise broad applications. Both research groups have proven records of commercializing research results including advanced supercomposites with nanofiber reinforced interfaces for military applications and spider silk fibers for tendon repair materials, sporting goods, and military protective materials. The two Universities will partner strategically to further develop and commercialize the unique ultrahigh-performance nanoflamentary synthetic spider silk fibers developed under this grant. Two PhD students with different backgrounds will interact and work closely with each other and the co-PIs. At least 5 undergraduates from both universities will also be involved with this research program. In addition senior design project groups will be joining the research to test various applications of these fibers. The proposed research covers biochemistry, mechanics, materials science, and nanomanufacturing and will provide students a unique interdisciplinary experience. Undergraduate students will present their results at Undergraduate Research Day. Both laboratories will be involved with their universities' efforts to recruit underrepresented groups, particularly providing laboratory tours and hands on efforts for high school students. A new nanostructured silk design, fabrication, and characterization testbed will be developed as part of the UNL Nanofiber Core Facility. This testbed will be used for demonstrations during frequent visits to our laboratories of fellow researchers, students, and members of the public in classes, and for research. This facility testbed will also serve as a vehicle for dissemination of new research results. Previous research from both groups has been featured in the popular press as well as several television programs both in the U.S. and in several other countries. Of specific note is that this research was featured on NSF's Science Nation program as well as Nova's "Making Stuff" and the Discovery, History and Disney Channels. The two groups will continue to jointly popularize this exciting research performed at the two universities.