Mimicking bio-lubrication by modifying hydrogel surfaces
Biological tissues such as articular cartilage or cornea provide ultralow friction with negligible wear over many decades. A large part of such unique lubrication properties is attributed to the confinement of fluid within the branched and brushy biomolecules at the surface. Synthetic hydrogels offer the possibility to tailor their surface properties on the nanoscale and therefore can be used to mimic various biological tissues. We have modified the surface structure of hydrogels by molding them against different materials. We have also developed a 2-step nano-indentation method to accurately determine rate-dependent stiffening effects of soft matter in liquid—a property characteristic of lubricious biological tissues such as cartilage or cornea. Understanding such lubrication mechanisms is crucial for designing synthetic replacements for cartilage, contact-lens materials or even coatings for medical instruments.
