Toward Zero Static Friction at the Microscale.

Static friction, a ubiquitous physical phenomenon, plays a significant role in natural processes and industrial applications. Its influence is particularly notable in the field of controlled micromanipulation and precision manufacturing, where static friction often exceeds kinetic friction and leads to material damage and unpredictable behaviors. In this study, we report the first experimental observation of the elimination of static friction peak in sliding micrometer contacts of layered materials, achieved through a technique involving selective etching of the amorphous edges of single crystalline surfaces.

Wear-free sliding electrical contacts with ultralow electrical resistivity.

Sliding electrical contacts are commonly applied in electrical connectors, such as conductive slip rings, pantographs, switches, and commutators. However, they suffer from several unavoidable problems caused by friction and wear, including high energy consumption, intermittent failures, limited life, and even failure disasters. In this study, we realized an ultralow-friction and long-distance wear-free state, defined as structural superlubricity (SSL), between sliding electrical interfaces under ambient conditions.

Filtering Robust Graphite without Incommensurate Interfaces by Electrical Technique.

Two-dimensional (2D) van der Waals (vdW) layered materials have attracted considerable attention due to their potential applications in various fields. Among these materials, graphite is widely employed to achieve structural superlubricity (SSL), where the interfacial friction between two solids is almost negligible and the wear is zero. However, the development of integrated SSL systems using graphite flakes still faces a major obstacle stemming from the inherent delamination-induced instability in vdW layered materials.

Computational Prediction of Superlubric Layered Heterojunctions.

Structural superlubricity has attracted increasing interest in modern tribology. However, experimental identification of superlubric interfaces among the vast number of heterojunctions is a trial-and-error and time-consuming approach. In this work, based on the requirements on the in-plane stiffnesses of layered materials and the interfacial interactions at the sliding incommensurate interfaces of heterojunctions for structural superlubricity, we propose criteria for predicting structural superlubricity between heterojunctions.