CAREER: Exploring the Recluse Spider's Strong Nanometer-Thin Silk Ribbons

非技术性摘要这项由威廉和玛丽学院材料研究部生物材料计划颁发的职业奖项是研究棕色隐居蜘蛛的带状丝状纤维的层次结构、机械和粘合性能，以及它形成更强的石墨烯-纳米复合材料的能力。蜘蛛丝具有出众的强度和韧性；同时，它们是以完全可持续的方式自然生产的，不使用石油、大量能源或任何有毒材料。作为天然材料，它们在医疗应用方面也很有趣，比如植入物。这种特性的结合使丝绸作为高性能材料非常有趣。在这个项目中，研究人员将研究形状独特的棕色隐居蜘蛛的丝质。与其他丝绸纤维不同的是，隐士的丝质不是圆柱形的，而是极其扁平而细小的丝带，就像微型的胶带--比人类的头发窄十倍，薄一千倍。这位研究人员之前的研究表明，这些丝带与最好的蜘蛛丝具有出色的机械性能；同时，它们独特的形状产生了有趣的新行为，如增强粘附性，并允许应用强大的分析工具。因此，本项目有望进一步加深我们对蚕丝及其微观结构的了解，并将详细揭示隐居蚕丝的一些独特特性，如粘性和强度。这一知识是将这种令人兴奋的材料用于未来工程和生物医学应用的直接先驱。该项目计划为从高中到研究生阶段的学生提供参与和学习经验。技术摘要这一职业奖项由威廉和玛丽学院材料研究部生物材料计划颁发，旨在研究棕色隐居蜘蛛的带状丝状纤维的层次结构、机械和粘合性能，以及它形成更强的石墨烯-纳米复合材料的能力。与许多其他合成或天然聚合物不同，这些真丝纤维是独立的、50 nm薄、5？m宽的蛋白质带。这位研究人员之前的研究表明，丝绸的拉伸性能与最强的丝绸相媲美；同时，它们独特的形态产生了新的特性，并允许使用原子力显微镜进行高分辨率的结构表征。隐逸丝带的结构比其他丝绸更简单，具有如此出色强度的薄丝绸薄膜是一种新奇的东西。由于它们很薄，这些丝带很容易弯曲，这使得它们可以最大限度地扩大与表面或接触到的物体的接触面积，从而实现更强的范德华粘附力。纳米乳突、球状纳米级表面特征可以进一步增强丝绸的粘性，这些特征在任何其他丝绸中都没有观察到。因此，隐居丝带将作为一个模型系统，以提高我们对丝绸的总体理解，并成为生物医用丝绸电影的基准。该项目的教育计划是为几个学科的本科生提供研究经验；并计划开展特别活动，以接触到高中生。这项研究将在新的本科生和研究生班级中利用倒置学习技术和数字技术进行展示。

Non-technical AbstractThis CAREER award by the Biomaterials program in the Division of Materials Research to College of William and Mary is to investigate ribbon-like silk fiber of the brown recluse spider with respect to its hierarchical structure, and mechanical and adhesive properties, as well as its ability to form even stronger hybrid graphene-nanocomposite materials. Spider silks have outstanding strength and toughness; at the same time, they are naturally produced in a fully sustainable way, not using petroleum, large amounts of energy, or any toxic materials. As natural materials, they are also interesting for medical applications, such as implants. This combination of properties makes silks highly interesting as high performance materials. In this project, the investigator will study the silk of the brown recluse spider, which has a unique shape. In contrast to the other silk fibers, the filaments of the recluse are not cylindrical, but extremely flat and thin ribbons, resembling miniaturized pieces of sticky tape - ten times narrower and one thousand times thinner than a human hair. Previous studies by this researcher have shown that these ribbons share the outstanding mechanical properties with the best spider silks; at the same time, their unique shape gives rise to interesting new behavior, such as enhanced adhesion, and it allows the application of powerful analytical tools. Therefore, this project is expected to further our understanding of silks and their microstructure in general, and will reveal some of the unique properties of recluse silk in detail, such as their stickiness, and strength. This knowledge is a direct precursor to exploiting this exciting material for future engineering and biomedical applications. This project plans to provide participation and learning experiences for students from high school to graduate levels.Technical AbstractThis CAREER award by the Biomaterials program in the Division of Materials Research to College of William and Mary is to investigate ribbon-like silk fiber of the brown recluse spider with respect to its hierarchical structure, and mechanical and adhesive properties, as well as its ability to form even stronger hybrid graphene-nanocomposite materials. Unlike many other synthetic or natural polymers, these silk fibers are freestanding, 50 nm-thin and 5 ìm-wide protein ribbons. Previous studies by this researcher showed that the tensile performance rivals the strongest silks; at the same time, their unique morphology gives rise to novel properties and allows high-resolution structural characterization using atomic force microscopy. The structure of the recluse ribbons is simpler than other silks; a thin silk film with such outstanding strength is a novelty. Due to their thinness, these silk ribbons bend easily, which allows them to maximize the contact area with surfaces or objects they are in contact, enabling stronger van der Waals adhesion. The stickiness may further be enhanced by the nano-papillae, globular nanoscale surface features, and these features have not been observed in any other silks. The recluse ribbons would thus serve as a model system to improve our understanding of silks in general, and as a benchmark for biomedical silk films. The educational plan of this project is to provide research experiences to undergraduates from several disciplines; and special activities are planned to reach out to high school students. The research will be featured in new undergraduate and graduate classes making use of inverted learning techniques and digital technology.