Scientists have made major progress in explaining friction, but predicting and controlling it still depends heavily on experiments. A comprehensive review examines the physics-based models behind friction, highlights why friction remains difficult to predict, and identifies key challenges that could make friction control more precise and reliable.

Increasing pavement skid resistance on a London highway by 50% reduced the total number of accidents over four years by 45%, according to the United Kingdom Transport and Road Research Laboratory. The United States National Transportation Safety Board and Federal Highway Administration stated that poor pavement skid resistance is a major cause of driving accidents. These are just two sources cited by an international team of researchers who recently reviewed more than 3,000 studies on tire-road friction and found that while tire-road friction theory and simulations have been well developed across the research scales — rubber-pavement scale, the tire-road scale and the vehicle scale — the scales themselves remain largely unconnected.

Rolling contact bearings are an important part of mechanical systems that reduce friction between moving parts. Scientists need to be able to accurately model these bearings so they can predict their performance, durability, and failure mechanisms. Even though significant advancements have been made, there is still a need for a unified framework to evaluate and compare the existing modeling approaches. A research team has studied the most significant rolling contact bearing models, identifying key trends and advancements. Their findings reveal a significant variability in the modeling approaches used and highlight the lack of standardized methodology for modeling these complex systems.

Researchers discovered a previously unknown polishing mechanism in bismuth, a promising layered material for future computer chips. Instead of being scratched or chemically pulled away during chemical mechanical polishing, bismuth forms a thin oxide layer that slips sideways, enabling unusually rapid material removal. The findings contribute to future advances in semiconductor manufacturing.

In the fields of material science and engineering, understanding the principles of wear and friction is pivotal for the development and optimization of materials and mechanical systems. A research team has synthesized the current research on wear modeling and friction-induced noises, exploring their mechanisms, influencing factors, and predictive challenges.  By studying wear modeling and friction-induced noise, engineers are better able to predict the lifespans of components and prevent structural failure across a wide range of industries.

To address this limitation, research teams led by Prof. Kai Zhang (University of Göttingen) and Prof. Rongxin Su (Tianjin University) have developed an integrated salt-assisted assembly (iSAA) that couples ion crosslinking with organic–inorganic co-assembly to construct nanofibril–crystal (NF-C) composite films exhibiting vivid, tunable interference colors. The work has been recently published in Research.