Friction is common in human’s daily life and production that may be either detrimental or beneficial. The friction law at microscale or even smaller scales nevertheless is lacking. In the present work, on the basis of JKR model for adhesive contact and by analogy with the emission of dislocations at a crack tip, the critical tangential force has been obtained for the onset of sliding. When the tangential force in adhesive contact induces a torque at the interface, a mechanical model for rolling adhesion has been presented on the basis of the assumption that it is governed by adhesion hysteresis. The critical torque and tangential force for rolling onset have been determined, which may be taken as measure for the rolling friction force. Comparisons with relevant experiments and models have been made to support the present concept. A kind of friction duality in small sized particles can thus be predicted.

摩擦在人类的日常生活和生产中很常见，它可能是有害的，也可能是有益的。然而，微尺度甚至更小尺度的摩擦定律仍然缺乏。在目前的工作中，基于粘附接触的 JKR 模型，并通过类比裂纹尖端位错的发射，已经获得了滑动开始的临界切向力。当粘合剂接触中的切向力在界面处引起扭矩时，基于粘附力滞后控制的假设，已经提出了滚动粘附力的机械模型。已经确定了滚动开始的临界扭矩和切向力，可以作为滚动摩擦力的度量。已经与相关实验和模型进行了比较以支持当前的概念。