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Full-Text Articles in Mechanical Engineering
Atomic Roughness Enhanced Friction On Hydrogenated Graphene, Yalin Dong, Xiawa Wu, Ashlie Martini
Atomic Roughness Enhanced Friction On Hydrogenated Graphene, Yalin Dong, Xiawa Wu, Ashlie Martini
Dr. Yalin Dong
Atomic friction on hydrogenated graphene is investigated using molecular dynamics simulations. Hydrogenation is found to increase friction significantly, and the atomic-level information provided by the simulations reveals that atomic roughness induced by hydrogenation is the primary cause of the friction enhancement. Other proposed mechanisms, specifically adhesion and rigidity, are excluded based on the simulation results and analyses performed using the Prandtl–Tomlinson model. In addition, it is found that friction does not monotonically increase with hydrogen coverage on the graphene surface; instead, a maximum friction is observed at a hydrogen coverage between 5 and 10%.
Effects Of Substrate Roughness And Electron–Phonon Coupling On Thickness-Dependent Friction Of Graphene, Yalin Dong
Effects Of Substrate Roughness And Electron–Phonon Coupling On Thickness-Dependent Friction Of Graphene, Yalin Dong
Dr. Yalin Dong
Molecular dynamics simulation and the two-temperature method are carried out to model the effects of substrate roughness as well as electron–phonon coupling on thickness-dependent friction on graphene. It is found that substrate roughness can significantly enhance friction of graphene, which is orders of magnitude larger than that on smooth substrate due to puckering effect. Additionally, the adhesive force between graphene and substrate plays opposite roles for smooth and rough substrates. While on a smooth substrate, a larger adhesion hinders the wrinkle formation in graphene, therefore suppressing friction, on a rough substrate, adhesion helps induce atomic roughness in graphene and leads …