micro/nano-scale friction (rus. трение на микро/нано-масштабном уровне) — interaction between solids as they slide, which takes place in the thin (in the scale of micro-nanometres) surface layers and is controlled by roughness or subroughness of the surfaces, thin interfacial film properties and adhesive properties of the surfaces.

Description

Friction in the micro-nanoscale has a number of features compared to conventional friction interaction, which includes both a deformation and a molecular component. First of all, the fractal structure of the surface plays an important role, which is manifested as new levels of surface roughness, which emerge at each new stage of downscaling of the friction object modeling and have typical dimensions corresponding to the scale under consideration. Also, variation is observed in the shape and the distribution of irregularities, etc. Second, as the scale goes down, adhesion forces come to play a critical role, while the deformation component becomes less important. This complicates the determination of the real contact surface between two bodies and their friction modeling as their boundary is substantially curved by molecular forces. At the level of individual atoms, quantum physics becomes essential, and experimental studies grow more and more complicated. Thus, for example, the experiment that was conducted in 2008 to study the friction when moving a single cobalt atom on a copper substrate required cooling to 5 K, creating an ultra-high vacuum and a special design of the atomic force microscope.

Authors

  • Goryacheva Irina G.
  • Shpenеv Alexey G.

Sources

  1. Ternes M. et al. The Force Needed to Move an Atom on a Surface // Science. 2008. V. 319, №5866. P. 1066–1069.
  2. Mo Yifei et al. Friction laws at the nanoscale // Nature. 2009. V. 457. P. 1116–1119.