Simulations of Simple Nanomachines in Carbon Nanotude Bundles Based on Chirality
Abstract
Single-walled carbon nanotubes (CNTs) have been studied extensively since their discovery and identification by Iijima in 1993. Their impressive mechanical, electrical, and thermal properties have created new fields of study, and the benefits of this research are just beginning to be realized. One potential use of CNTs is as a foundation for nanomachines. Another possible use, one that takes advantage of their mechanical properties, is the synthesis of high-strength, low-weight materials that could revolutionize infrastructure materials. A significant problem facing researchers for either of these applications is in finding techniques to engineer the load transfer between nanotubes. For applications in strong materials, maximizing the coupling between carbon nanotubes is important; for molecular machine applications, inducing relative motion and/or reducing friction between molecules is desired. In the simulations reported herein, we examined seven periodic tube bundles arranged in a horizontal closest packing (HCP) array using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) molecular dynamics code. The forces required to move the center tube through the bundle were recorded using the LAMMPS program. Each chirality type and diameter produced a different force function as the van der Waals forces 'rubbed' against each other. One property discovered through the simulations is that certain chirality combinations produce useful behavior during the pullout process. One such behavior is the ultra-low frictional resistance experienced by certain bundles, which could improve efficiency within nano-oscillators. Another discovery is the rotation induced by extraction, both in center tubes and in the outer tubes, which could serve as the foundation for a nanogear system. The final behavior involves removing the freedom of rotation within the system, which greatly increases the magnitude of load transfer during extraction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2008
- Accession Number
- ADA505707
Entities
People
- C. F. Cornwell
- C. R. Welch
- D. L. Majure
- N. J. Lee
- Richard Haskins
Organizations
- Engineer Research and Development Center