van Baarle Dirk W, Krylov Sergey Yu, Beck M E Stefan, Frenken Joost W M
1Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands.
2Huygens - Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
Tribol Lett. 2019;67(1):15. doi: 10.1007/s11249-018-1127-6. Epub 2018 Dec 31.
Friction between two surfaces is due to nano- and micro-asperities at the interface that establish true contact and are responsible for the energy dissipation. To understand the friction mechanism, often single-asperity model experiments are conducted in atomic-force microscopes. Here, we show that the conventional interpretation of the typical results of such experiments, based on a simple mass-spring model, hides a fundamental contradiction. Via an estimate of the order of magnitude of the dissipative forces required to produce atomic-scale patterns in the stick-slip motion of a frictional nano-contact, we find that the energy dissipation must be dominated by a very small, highly dynamic mass at the very end of the asperity. Our conclusion casts new light on the behavior of sliding surfaces and invites us to speculate about new ways to control friction by manipulation of the contact geometry.
两个表面之间的摩擦力是由于界面处的纳米和微米级粗糙不平度造成的，这些粗糙不平度形成了真正的接触并导致能量耗散。为了理解摩擦机制，人们常常在原子力显微镜中进行单峰模型实验。在此，我们表明，基于简单的质量 - 弹簧模型对这类实验典型结果的传统解释隐藏着一个基本矛盾。通过估算在摩擦纳米接触的粘滑运动中产生原子尺度图案所需的耗散力的量级，我们发现能量耗散必定主要由峰端一个非常小的、高度动态的质量主导。我们的结论为滑动表面的行为提供了新的见解，并促使我们思考通过操纵接触几何形状来控制摩擦的新方法。
