2018/03/12 by Banafsheh Sajadi, Sajadi, Banafsheh, Simon van Hemert +9
Materials Science · Physics and Astronomy · Engineering · #Graphene research and applications #Mechanical and Optical Resonators #Nanopore and Nanochannel Transport Studies
paper · pdf · doi:10.48550/arxiv.1803.04191
The bending rigidity of two-dimensional (2D) materials is a key parameter for\nunderstanding the mechanics of 2D NEMS devices. The apparent bending rigidity\nof graphene membranes at macroscopic scale differs from theoretical predictions\nat micro-scale. This difference is believed to originate from thermally induced\ndynamic ripples in the atomically thin membrane. In this paper, we perform\nmodal analysis to estimate the effective macroscopic bending rigidity of\ngraphene membranes from the frequency spectrum of their Brownian motion. Our\nmethod is based on fitting the resonance frequencies obtained from the Brownian\nmotion in molecular dynamics simulations, to those obtained from a continuum\nmechanics model, with bending rigidity and pretension as the fit parameters. In\nthis way, the effective bending rigidity of the membrane and its temperature\nand size dependence, are extracted, while including the effects of dynamic\nripples and thermal fluctuations. The proposed method provides a framework for\nestimating the macroscopic mechanical properties at high frequencies in other\ntwo-dimensional nano-structures at finite temperatures.\n