Wrinkling of monolayer graphene: A study by molecular dynamics and continuum plate theory

(2014) Mechanical properties investigation of monolayer h-BN sheet under in-plane shear displacement using molecular dynamics simulations. Journal of Applied Physics, 115 (1). 014308. Permanent WRAP url: http://wrap.warwick.ac.uk/76452 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher's statement:Copyright ( as well as temperature on the fracture behavior have also been studied to obtain further insights into the properties of the monolayer h-BN sheet.

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“…Those wrinkles can be obtained by various external loads. Wang [26] utilized an indenter trip tip of diameter 0.535nm…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties investigation of monolayer h-BN sheet under in-plane shear displacement using molecular dynamics simulations

Tian

Gao

et al. 2014

Journal of Applied Physics

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“…9 Numerical simulations have been done to understand the formation of wrinkles and their impact on graphene. [10][11][12][13] Wrinkles are commonly found in chemical-vapor-deposition (CVD) grown graphene that is transferred to other substrates. [14][15][16][17] In CVD, graphene wrinkles are formed at metal step edges due to thermal stress.…”

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confidence: 99%

Formation and control of wrinkles in graphene by the wedging transfer method

Calado

Schneider²,

Theulings³

et al. 2012

Applied Physics Letters

124

101

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We study the formation of wrinkles in graphene upon wet transfer onto a hydrophilic target substrate, whereby draining of water appears to play an important role. We are able to control the orientation of the wrinkles by tuning the surface morphology. Wrinkles are absent in flakes transferred to strongly hydrophobic substrates, a further indication of the role of the interaction of water with the substrate in wrinkle formation. The electrical and structural integrity of the graphene is not affected by the wrinkles, as inferred from Raman measurements and electrical conductivity measurements. Graphene has received a lot of attention since its isolation from graphite.1 Although graphene is a 2D crystal, it is so far only found on a substrate, as a membrane with a supporting construction 2 or grown at the surface of SiC. 3 Therefore, it is considered to be a quasi 2D crystal. Quasi-2D graphene is in general not flat, but has a tendency to form corrugations, including ripples, wrinkles, and bubbles.2,4 The curvature associated with such corrugations is predicted to alter graphene's electronic and structural properties. 5,6 Corrugations are often regarded as undesirable, but they can be exploited for inducing pseudo-magnetic fields, 7 creating chemically reactive sites, 8 and for specific device applications such as optical lenses. 9 Numerical simulations have been done to understand the formation of wrinkles and their impact on graphene. [10][11][12][13] Wrinkles are commonly found in chemical-vapor-deposition (CVD) grown graphene that is transferred to other substrates.14-17 In CVD, graphene wrinkles are formed at metal step edges due to thermal stress. The morphology of the metal growth surface can still be seen after transfer. In many cases, additional wrinkles, ripples, and bubbles are formed upon transfer. Exfoliated graphene mostly conforms to the corrugations of the underlying substrate, 18 although small additional wrinkles can be observed in a scanning tunnelling microscope. 19In this work, we study the formation of wrinkles in graphene during the so-called wedging transfer process, a water-based transfer process. 20 We give insight in the driving forces for wrinkle formation and suggest different routes to control the wrinkle orientation and abundance, or to eliminate wrinkles altogether. We also examine to what extent the electronic and structural integrity of graphene is preserved upon wrinkle formation.The wrinkle formation can be easily seen with an optical microscope, as illustrated for a graphitic flake in Fig. 1 (the entire process is carried out under ambient conditions). Graphitic flakes of varying thicknesses are prepared by mechanical exfoliation of graphite (NGS Naturgraphit GmbH) on Si substrates with a 285 nm thermal oxide. A hydrophobic polymer film covers the substrate (Fig. 1(a)), and is "wedged off" the substrate by intercalation of water ( Fig. 1(b)), along with the graphitic flakes. As a result, the film with the flakes is floating on top of the water surface ( Fig. 1(c)). Then the wate...

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“…On the other hand, molecular dynamics (MD) simulations have often been employed for scales of length much smaller than micrometers, due to the intractable computational expense that would be incurred for a direct experimental comparison. There have been numerous examples of MD simulations of nanoindentation of a variety of nanometer materials [4][5][6]. However, to the authors' knowledge, no atomistic simulation of the pressure bulge test has been reported for the analysis of the nonlinear elastic properties of atomic layers, in particular nanometer-sized graphene monolayers, which motivates the current study.…”

Section: Introductionmentioning

confidence: 96%

Size Dependence of the Nonlinear Elastic Softening of Nanoscale Graphene Monolayers under Plane-Strain Bulge Tests: A Molecular Dynamics Study

Jun

Tashi

Park

2011

Journal of Nanomaterials

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The pressure bulge test is an experimental technique to characterize the mechanical properties of microscale thin films. Here, we perform constant-temperature molecular dynamics simulations of the plane-strain cylindrical bulge test of nanosized monolayer graphene subjected to high gas pressure induced by hydrogen molecules. We observe a nonlinear elastic softening of the graphene with an increase in hydrogen pressure due to the stretching and weakening of the carbon-carbon bonds; we further observe that this softening behavior depends upon the size of the graphene monolayers. Our simulation results suggest that the traditional microscale bulge formulas, which assume constant elastic moduli, should be modified to incorporate the size dependence and elastic softening that occur in nanosized graphene bulge tests.

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Wrinkling of monolayer graphene: A study by molecular dynamics and continuum plate theory

Cited by 78 publications

References 48 publications

Mechanical properties investigation of monolayer h-BN sheet under in-plane shear displacement using molecular dynamics simulations

Mechanical properties investigation of monolayer h-BN sheet under in-plane shear displacement using molecular dynamics simulations

Formation and control of wrinkles in graphene by the wedging transfer method

Size Dependence of the Nonlinear Elastic Softening of Nanoscale Graphene Monolayers under Plane-Strain Bulge Tests: A Molecular Dynamics Study

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