Structural superlubricity in large-scale heterogeneous layered material junctions

Abstract Structural superlubricity is a fascinating phenomenon where the friction is ultralow due to the lateral interaction cancellation resulted from incommensurate contact crystalline surfaces. During the past decade, various kinds of nano- and microscale materials such as two-dimensional materials, metals, and compounds have been used for the fabrication. Among them, layered materials junctions are most widely used due to their ease of fabrication to achieve superlubricity. For homogeneous junction where superlubricity was initially observed, superlow friction forces exist in most relative orientations with incommensurate configuration. Heterojunctions, however, bear no resemblance to homogeneous contacts, since the lattice constants are naturally mismatched which lead to a robust structural superlubricity with any orientation of the two different surfaces. In this chapter, we focus on the latter part with short introduction to the homogenous junctions. Special emphasis is made on the large-scale superlubric systems due to their great potential in applications.