Biotribology

Biotribology is the study of friction, wear, and lubrication in biological systems. It examines how tissues and materials interact under contact, sliding, and rolling in environments with body fluids, complex loads, and dynamic motion. The field encompasses natural tissues such as bone, cartilage, tendon, and teeth, as well as artificial materials used in medical devices, implants, and dental prostheses.

In joints, synovial fluid provides lubrication, with components such as lubricin and hyaluronan contributing to boundary and fluid-film lubrication. Cartilage surface roughness, proteoglycan content, and lubrication regime determine friction under varying speeds and loads, including boundary, hydrodynamic, and elastohydrodynamic conditions.

Biotribology also addresses wear and damage, including cartilage degeneration and implant wear particles that can trigger inflammation. Wear mechanisms include adhesive, abrasive, and fatigue wear in tissues and devices, as well as material degradation under repetitive or high-load conditions.

Measurement and modeling employ tribometers and tests such as pin-on-disk or reciprocating sliding, across micro- to macro-scales. Models of contact mechanics and lubrication regimes (often using Stribeck curves) help predict friction and wear and guide surface design and material selection.

Applications include improved joint and dental implants, biocompatible coatings, lubricants, and rehabilitation strategies. Ongoing research links molecular biology of boundary lubricants with nanoscale surface engineering and personalized tribology to reduce wear and inflammation in orthopedic care.