How Graphene Slides: Measurement and Theory of Strain-Dependent Frictional Forces between Graphene and SiO2
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- 作者：Alexander L. Kitt ; Zenan Qi ; Sebastian R茅mi ; Harold S. Park ; Anna K. Swan ; Bennett B. Goldberg
- 刊名：Nano Letters
- 出版年：2013
- 出版时间：June 12, 2013
- 年：2013
- 卷：13
- 期：6
- 页码：2605-2610
- 全文大小：310K
- 年卷期：v.13,no.6(June 12, 2013)
- ISSN：1530-6992
文摘
Strain, bending rigidity, and adhesion are interwoven in determining how graphene responds when pulled across a substrate. Using Raman spectroscopy of circular, graphene-sealed microchambers under variable external pressure, we demonstrate that graphene is not firmly anchored to the substrate when pulled. Instead, as the suspended graphene is pushed into the chamber under pressure, the supported graphene outside the microchamber is stretched and slides, pulling in an annulus. Analyzing Raman G band line scans with a continuum model extended to include sliding, we extract the pressure dependent sliding friction between the SiO2 substrate and mono-, bi-, and trilayer graphene. The sliding friction for trilayer graphene is directly proportional to the applied load, but the friction for monolayer and bilayer graphene is inversely proportional to the strain in the graphene, which is in violation of Amontons鈥?law. We attribute this behavior to the high surface conformation enabled by the low bending rigidity and strong adhesion of few layer graphene.