EAGER: From Mechanics of the Eshelby Twist to Nanotube Chirality

William Marsh Rice University, Houston TX

Investigators

Abstract

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.