Influence of Various Defect Parameters on the Vibration Characteristics of a Single-Walled Carbon Nanotube
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TECHNICAL ARTICLE—PEER-REVIEWED
Influence of Various Defect Parameters on the Vibration Characteristics of a Single-Walled Carbon Nanotube Mohit Goel . S. P. Harsha . M. P. Mishra . R. K. Mishra
Submitted: 7 July 2020 ASM International 2020
Abstract Free vibration response of the single-walled carbon nanotubes (SWCNTs) is investigated using molecular dynamics simulation. Vibrational analysis is performed to study the effects of various defect parameters such as aspect ratio, chirality, presence of vacancy defects, numbers of defects and their position along the length of the SWCNT. The effects of these features on the natural vibration of SWCNTs are studied by determining the change in fundamental natural frequencies due to these features. Dynamics simulations are performed for cantilever boundary condition. Vibrational response obtained through molecular dynamic simulations indicates that shorter tubes offer higher vibrational sensitivity. Chirality effect is found to diminish with the increase in the length of tube. It is also found that the number of defects and their position along the tube affect greatly the natural frequency of the SWCNT. This study will provide invaluable input to the designers and users of carbon nanotube in the field of high-sensitive sensor application. Keywords Carbon nanotube Molecular dynamics Chirality Vacancy defect
M. Goel M. P. Mishra Instruments Research and Development Establishment, Dehradun 248 008, India M. Goel S. P. Harsha Vibration and Noise Control Laboratory, Mechanical and Industrial Engineering Department, Indian Institute of Technology Roorkee, Roorkee 247 667, India R. K. Mishra (&) Regional Centre for Military Airworthiness, Bangalore, India e-mail: [email protected]
Introduction Owing to the remarkable mechanical and vibrational characteristics of single-walled carbon nanotubes (SWCNTs), nanomechanical resonators made of carbon nanotubes have attracted much attention [1–5]. These resonators can generate ultra-high resonant frequencies up to the order of giga hertz [6] making them ideal candidates for applications in nanosensors for detection of atoms/molecules [7], biomedical sensors, nanopumping devices for molecular transportation [8], mass detectors [9, 10], etc. It has been reported that micro-mechanical resonators can detect the mass as small as femtograms by using silicon or silicon nitride cantilevers [11]. That’s why resonators are scaled down to nanosize, resulting in enhanced mass sensitivity. Poncharal et al. [12] have predicted that fundamental frequencies of cantilevered or bridged singlewalled carbon nanotubes could reach the level of 10 GHz– 1.5 THz depending on the nanotube’s diameter and length. Since the performance of nanomechanical resonator for sensing applications is highly correlated with their vibrational characteristics, it is of great significance to gain a full understanding of the vibrational properties of SWCNTs [13, 14]. Most of the reported research work on nanomechanical resonator is based upon the pristine SWCN
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