Friction laws at the nanoscale Export

@article{citeulike:4104706, abstract = {Macroscopic laws of friction do not generally apply to nanoscale contacts. Although continuum mechanics models have been predicted to break down at the nanoscale1, they continue to be applied for lack of a better theory. An understanding of how friction force depends on applied load and contact area at these scales is essential for the design of miniaturized devices with optimal mechanical performance2, 3. Here we use large-scale molecular dynamics simulations with realistic force fields to establish friction laws in dry nanoscale contacts. We show that friction force depends linearly on the number of atoms that chemically interact across the contact. By defining the contact area as being proportional to this number of interacting atoms, we show that the macroscopically observed linear relationship between friction force and contact area can be extended to the nanoscale. Our model predicts that as the adhesion between the contacting surfaces is reduced, a transition takes place from nonlinear to linear dependence of friction force on load. This transition is consistent with the results of several nanoscale friction experiments4, 5, 6, 7. We demonstrate that the breakdown of continuum mechanics can be understood as a result of the rough (multi-asperity) nature of the contact, and show that roughness theories8, 9, 10 of friction can be applied at the nanoscale.}, author = {Mo, Yifei and Turner, Kevin T. and Szlufarska, Izabela}, citeulike-article-id = {4104706}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/nature07748}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/nature07748}, day = {26}, doi = {10.1038/nature07748}, issn = {0028-0836}, journal = {Nature}, keywords = {clip2, md, physics, simulation}, month = {February}, number = {7233}, pages = {1116--1119}, posted-at = {2009-03-11 08:45:11}, priority = {2}, publisher = {Nature Publishing Group}, title = {Friction laws at the nanoscale}, url = {http://dx.doi.org/10.1038/nature07748}, volume = {457}, year = {2009} }

TY - JOUR ID - citeulike:4104706 L3 - citeulike-article-id:4104706 N2 - Macroscopic laws of friction do not generally apply to nanoscale contacts. Although continuum mechanics models have been predicted to break down at the nanoscale1, they continue to be applied for lack of a better theory. An understanding of how friction force depends on applied load and contact area at these scales is essential for the design of miniaturized devices with optimal mechanical performance2, 3. Here we use large-scale molecular dynamics simulations with realistic force fields to establish friction laws in dry nanoscale contacts. We show that friction force depends linearly on the number of atoms that chemically interact across the contact. By defining the contact area as being proportional to this number of interacting atoms, we show that the macroscopically observed linear relationship between friction force and contact area can be extended to the nanoscale. Our model predicts that as the adhesion between the contacting surfaces is reduced, a transition takes place from nonlinear to linear dependence of friction force on load. This transition is consistent with the results of several nanoscale friction experiments4, 5, 6, 7. We demonstrate that the breakdown of continuum mechanics can be understood as a result of the rough (multi-asperity) nature of the contact, and show that roughness theories8, 9, 10 of friction can be applied at the nanoscale. IS - 7233 JF - Nature SN - 0028-0836 EP - 1119 TI - Friction laws at the nanoscale PB - Nature Publishing Group VL - 457 SP - 1116 KW - clip2 KW - md KW - physics KW - simulation AU - Mo, Yifei AU - Turner, Kevin AU - Szlufarska, Izabela PY - 2009/02/26/ UR - http://dx.doi.org/10.1038/nature07748 ER -