Recent advances in lubrication mechanisms of electrospun nanofibers: Oil-mediated and non-oil strategies

Friction and wear develop inherently at the dynamic interfaces of moving devices, leading to considerable energy losses and shortened lifespans. To overcome these challenges beyond conventional methods, precise structural control of the contact interface is essential, and developing tailored lubricating structures is therefore imperative for modern machinery. By exploiting the high specific surface area, aspect ratio, and porosity, together with the interconnected three-dimensional network structure of electrospun nanofibers, this review discusses the effects of surface morphology on lubricant behavior. Low-friction systems based on electrospun nanofibers are classified as oil-mediated self-lubricating nanofibers and non-oil interfacial and structural low-friction nanofibers. In oil-mediated systems, core-shell nanofibers store and release liquid lubricants from their internal cores, whereas non-core-shell nanofiber networks retain and structure oil to maintain an oil-rich lubricating environment. In addition, the friction reduction mechanisms are analyzed by focusing on lubricant storage and release, oil structuring, formation of hydration- and ion-based interfacial lubrication layers, reduction of interfacial shear resistance by solid lubricants, and the mechanical load-bearing effect of the nanofiber network. This review summarizes how nanofiber structure and material composition govern the friction and wear behavior of these systems.