Biomimetic design of UHMWPE bearing interfaces lubricated through boundary-fluid mixed mechanism for artificial joints

Abstract

Natural articular cartilage, devoid of lymph and blood vessels, has limited self-repair capacity but can function for up to 70 years. Its remarkable longevity is attributed to its porous, water-containing structure and lubrication from brushlike polymers. In this study, simulating structure and lubrication mechanism of natural articular cartilage, a composite structure incorporating pores and brushlike polymers was constructed on bearing interface of UHMWPE artificial joint. The biomimetic bearing interface achieved a boundary-fluid mixed lubrication mechanism, demonstrating ultra-high wettability (0° contact angle) and low friction coefficient (0.03) comparable to that of natural articular cartilage, while also exhibiting a relatively long lifespan. This study presents a promising technology for fabricating super-lubricated bearing interfaces mimicking natural cartilage and elaborates a unique lubrication mechanism.