Chapter 8 - Toward micro- and nanoscale robust superlubricity by 2D materials

Abstract

Although showing a high potential in tribological systems, superlubricity of two-dimensional (2D) materials faces several challenges to stay robust in real sliding interfaces, for example, interfacial orientation dependence, sensitivity to environmental atmosphere, scalability to large length scales, etc. This chapter reviews some theoretical and experimental attempts to tackle these problems. Firstly, superlubricious state for heterogeneous interface between 2D materials with large lattice mismatch has been predicted. The superlubricity has been attributed to the negligible interfacial charge density fluctuation during sliding, and has been realized at both nanoscale and microscale. Secondly, multicontact modes with random interfacial orientation at contacting asperities have been observed, which again can be achieved at both microscale and macroscale. Thirdly, the nanoscale wear mechanism and schemes to design wear resistant systems have been provided. So far, application of 2D materials is still hindered by the present preparation techniques, harsh working conditions, etc. Theoretical modeling and experimental measurement of energy dissipation in friction may be a main direction for future study of superlubricity.