2006/06/22 by Binquan Luan, Mark O. Robbins · 2 citations
Engineering · Materials Science · Physics and Astronomy · #Adhesion, Friction, and Surface Interactions #Diamond and Carbon-based Materials Research #Force Microscopy Techniques and Applications #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physreve.74.026111
arxiv created 2006/06/22 · openalex publication_date 2006/08/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Atomistic simulations are used to test the equations of continuum contact mechanics in nanometer scale contacts. Nominally spherical tips, made by bending crystals or cutting crystalline or amorphous solids, are pressed into a flat, elastic substrate. The normal displacement, contact radius, stress distribution, friction, and lateral stiffness are examined as a function of load and adhesion. The atomic scale roughness present on any tip made of discrete atoms is shown to have profound effects on the results. Contact areas, local stresses, and the work of adhesion change by factors of 2 to 4, and the friction and lateral stiffness vary by orders of magnitude. The microscopic factors responsible for these changes are discussed. The results are also used to test methods for analyzing experimental data with continuum theory to determine information, such as contact area, that cannot be measured directly in nanometer scale contacts. Even when the data appear to be fit by continuum theory, extracted quantities can differ substantially from their true values.