A glance into the boundary lubrication mechanism of PVA hydrogel after the reduction of interstitial fluid pressurization

The present study introduces a tribological comparison of five polyvinyl alcohol (PVA) hydrogel specimens with different physiological properties and possible candidate materials for cartilage replacement. The superior lubrication of articular cartilage is believed to lie in solid-to-solid molecular interactions. Therefore, the focus was paid to the investigation of boundary lubrication with regard to interstitial fluid flow reduction. The experiments were carried out in a ball-on-plate (glass-on-hydrogel) configuration. Based on the experiments, we proposed a boundary lubrication mechanism, selected a hydrogel with the least surface damage, and highlighted the desired properties that should be considered when developing the artificial cartilage.