Hydrogels, with their tissue-like properties, biocompatibility, and soft properties, are potential biomimetic cartilage replacement materials. However, the conflict between their surface lubricity and load-bearing properties significantly limits their application. Here, we developed a structure-based hydrogel with super-lubricity and high load-bearing properties. Through ultraviolet (UV)-controlled dissociation, a gradient hydrogel surface was constructed. This structure effectively dissipates normal contact stress while maintaining a high surface hydration level, enhancing load-bearing capacity. Furthermore, micron-sized spherical gel particles were prepared using an emulsion method and incorporated into the highly hydrated polymer network, further enhancing the load-bearing capacity of the porous hydrogel and significantly reducing the coefficient of friction (COF) by converting sliding friction into rolling friction. Ultimately, through multiple synergistic effects, we achieved ultra-low friction performance, with a COF of approximately 0.0064 after 20,000 cycles under a 5 N load. This innovation provides an alternative solution for future biomimetic articular cartilage.

In this study, a polymer gelator containing urea groups and dynamic disulfide bonds was prepared using the method of free radical aggregation. When added to base oil, it formed a tight and dynamic supramolecular network structure through the synergistic effect of dynamic covalent and non-covalent, exhibiting excellent mechanical adaptability while improving the heat resistance of lubricating oil. The tribological behavior of the prepared gel lubricants was comprehensively evaluated. The results revealed that the gel lubricants outperformed the base oil, exhibiting markedly lower friction coefficients (COFs), reduced wear rates, delivering exceptional extreme pressure resistance, and maintaining functionality in challenging and severe operating environments. Specifically, the gel lubricants delivered a 30% reduction in COF, 89% decrease in wear volume, and a maximum load-bearing capacity of 1500 N. Moreover, the gel lubricant enhanced the viscoelasticity of the base oil, promoting the formation of both an adsorbed film and a tribochemical protective film at the friction interface, which resulted in good tribological performance under fully lubricated conditions. The gel lubricant delivers exceptional tribological functionality while playing a pivotal role in eliminating environmental hazards caused by creep-induced oil leakage.