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Updated: Jan 6, 2026

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Transparency of Graphene to Solid-Solid van der Waals Interactions
Chuanli Yu1, Weijia Zeng1, Zepu Kou2
1Peking University, School of Mechanics and Engineering Science, State Key Laboratory for Turbulence and Complex Systems, Beijing 100871, China.
Abstract:
Understanding the transparency of two-dimensional (2D) materials to intermolecular interactions-particularly their ability to transmit van der Waals (vdW) forces-is crucial for applications such as the design of 2D material-based nanofluidic and microelectromechanical systems. However, experimental studies have produced inconsistent and even contradictory conclusions regarding the vdW transparency of 2D materials. Here, we employ colloidal atomic force microscopy with a geometrically well-defined probe to measure pull-off and pull-in forces in a model system: graphene on silicon dioxide (SiO_{2}). Our results reveal that the total vdW force deviates significantly from the naive sum of contributions from graphene and its substrate. Intriguingly, the measured pull-off forces indicate that the effective surface energy of a suspended graphene monolayer can exceed that of its substrate-supported counterpart. Furthermore, our measurements of pull-in forces in substrate-supported systems suggest that graphene of 1-5 layers screens 15%-50% of the intrinsic solid-solid vdW interaction, consistent with Lifshitz theory calculations.
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