Size- and temperature-dependent bending rigidity of graphene using modal analysis

Size- and temperature-dependent bending rigidity of graphene using modal analysis

Sajadi, B. (TU Delft Dynamics of Micro and Nano Systems)
van Hemert, Simon (Student TU Delft)
Arash, B. (TU Delft Applied Mechanics)
Belardinelli, P. (TU Delft Dynamics of Micro and Nano Systems)
Steeneken, P.G. (TU Delft Dynamics of Micro and Nano Systems; TU Delft QN/Steeneken Lab)
Alijani, F. (TU Delft Dynamics of Micro and Nano Systems)

2018

The bending rigidity of two-dimensional (2D) materials is a key parameter for understanding the mechanics of 2D NEMS devices. The apparent bending rigidity of graphene membranes at macroscopic scale differs from theoretical predictions at micro-scale. This difference is believed to originate from thermally induced dynamic ripples in these atomically thin membranes. In this paper, we perform modal analysis to estimate the effective bending rigidity of graphene membranes from the frequency spectrum of their Brownian motion. Our method is based on fitting the resonance frequencies obtained from the Brownian motion in molecular dynamics simulations, to those obtained from a continuum mechanics model, with bending rigidity and pretension as the fit parameters. In this way, the effective bending rigidity of the membrane and its temperature and size dependence, are extracted, while including the effects of dynamic ripples and thermal fluctuations. The proposed method provides a framework for estimating the macroscopic mechanical properties in other 2D nanostructures at finite temperatures.

Bending rigidity
Brownian motion
Characterization
Graphene
Molecular dynamics
Multi-modal approach

http://resolver.tudelft.nl/uuid:9e899872-b10f-43de-a12e-62ec5e62f383

https://doi.org/10.1016/j.carbon.2018.06.066

0008-6223

Carbon, 139, 334-341

Institutional Repository

journal article

© 2018 B. Sajadi, Simon van Hemert, B. Arash, P. Belardinelli, P.G. Steeneken, F. Alijani