Superlubricating electrical contact between graphite layers

High-conductivity sliding electrical contact with low friction plays a significance role in the long life and high reliability of electro-mechanical systems. Reducing friction needs weak interfacial electronic coupling, contradictorily, enhancing conductivity requires the strong coupling, thus it is a serious challenge to achieve high-conductivity with low friction. Here, using our self-developed TAMET method, we achieved superlubricating electrical contact experimentally by establishing sliding electrical system between graphite layers incommensurately; the friction coefficient is as low as 0.0004 and the electric current density is as high as 510 A/cm². Compared to the commercial Ir AFM tip-Gr contact, the friction force of incommensurate graphene layers friction is an order of magnitude lower, yet it has similar high electrical conductivity. Based on the Electronic Property Fluctuation (EPF) model and first principles calculations, we revealed that the sliding energy barrier remains almost unchanged under applied current due to the negligible electron transfer variation during the sliding process. We offer a method for achieving superlubricating electrical contact with high conductivity and low friction, shedding light into improving the service life and reliability of sliding electrical contacts in a wide range of electromechanical systems.