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Fabrication of Three-Dimensional Graphene-Based Polyhedrons via Origami-Like Self-Folding
Published on: September 23, 2018
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Switchable friction enabled by nanoscale self-assembly on graphene.
Patrick Gallagher1, Menyoung Lee1, Francois Amet2,3
1Department of Physics, Stanford University, Stanford, California 94305, USA.
Nature Communications
|February 24, 2016
Summary
Anisotropic friction in graphene arises from environmental adsorbates forming superlattices, not graphene ripples. These controllable stripe patterns allow for tunable frictional domains on graphene and hexagonal boron nitride surfaces.
Area of Science:
- Materials Science
- Tribology
- Surface Science
Background:
- Graphene exhibits anisotropic friction with twofold symmetry, previously attributed to nanoscale ripples.
- This friction anisotropy is significant, exceeding 200% in some cases.
Purpose of the Study:
- To investigate the origin of anisotropic friction domains in graphene.
- To determine if structural features or environmental factors cause this phenomenon.
Main Methods:
- Utilized scanning probe microscopy to observe and manipulate surface structures.
- Analyzed graphene and hexagonal boron nitride (hBN) flakes on various substrates.
- Investigated the role of environmental adsorbates in friction.
Main Results:
- Frictional domains are caused by self-assembled adsorbate superlattices, not graphene ripples.
- These stripe superlattices, with periods of 4-6 nm, are observed on graphene and hBN.
- Stripe patterns are controllable and reversible using scanning probe microscopy.
Conclusions:
- The anisotropic friction in graphene and related materials originates from adsorbate superlattices.
- This finding revises the understanding of friction mechanisms on 2D materials.
- Controllable adsorbate patterns offer new possibilities for tuning surface tribological properties.
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