EAGER: From Mechanics of the Eshelby Twist to Nanotube Chirality

这个研究项目奖的目的是迅速建立在总体概念，在一维结构的不同几何形状和拓扑结构的位错力学：纳米管，纳米线，和他们的原型建筑材料？石墨烯。位错的具体类型包括刃型位错线和螺型位错线，它们的作用截然不同。虽然刃位错动力学是很大程度上负责的非弹性力学响应，强度和塑性屈服（无论是在纳米管，或线，或石墨烯），螺旋位错发挥核心作用的形成机制的纳米线和？最近发现的？甚至纳米管。能量分析将在一系列结构上进行，以了解手性类型的分布如何随物体的拓扑结构而变化。值得注意的是，只有一种手性类型通常发生的线，而广泛的系统中产生的纳米管。我们将进一步扩大这项研究的生物学重要的微管，具有类似的机械结构，而积木是不同的规模和性质（微管蛋白二聚体）。可验证的内容将包括不同尺度和不同手征对称性的管状结构的量化分类，其弹性和非弹性力学模型，包括通过与实验比较进行验证，学生教育，文献记录和研究结果的传播。如果成功，该项目将导致对一类材料结构的拓扑构成的更深入和跨学科的理解，这些结构对于电子，强材料，细胞骨架动力学来说是重要和多样的。研究结果将通过出版物、专业会议和演示文稿向学生传播，从而有可能在学术界之外制造新设备和实现新技术。学生将受益于直接参与研究以及通过课堂教学，使他们接触到尖端的技术发展。这将对他们未来的职业生涯产生长期的影响。

The objective of this research project award is to rapidly build on the overarching concept, a dislocation mechanics in one-dimensional structures of different geometries and topologies: nanotubes, nano-wires, and their archetypal building material?graphene. The specific types of dislocations include the edge and the screw dislocation lines with distinctly different roles. While the edge dislocation dynamics is greatly responsible for the inelastic mechanical response, strength and plastic yield (either in nanotubes, or wires, or graphene), the screw dislocations play central role in the formation mechanisms of nanowires and?as recently discovered?even nanotubes. The energy analysis will be performed on the range of structures in order to understand how the distribution of chiral types varies with the topology of the objects. Notably, only one chiral type normally occurs for the wires, while a broad range is systematically produced among the nanotubes. We will further expand this study to biologically important microtubules, which have analogous mechanical constitution, while the building blocks are of different scale and nature (tubulin dimers). Deliverables will include the quantified classification of tubular structures of different scales and different chiral symmetries, models of their elastic and inelastic mechanics, including validation through comparison with experiments, student education, documentation and dissemination of research results. If successful, this project will lead to deeper and cross-disciplinary understanding of topological makeup of a class of material structures, important and diverse as for electronics, strong materials, cytoskeleton dynamics. The results will be disseminated through publications, professional conferences, and presentations to students to potentially enable making new devices and enabling new technologies outside the academia. Students will benefit from the direct involvement in research as well as through classroom instruction, exposing them to the cutting-edge technological developments. This will have a long-lasting impact as they embark in their future careers.