A study will be made of the fundamental nature of boundary lubrication of biological contacts. Friction force microscopy will be used to study the boundary layer lubricant properties of biological fluids at the molecular level. It is hypothesized that chain molecules of poly (ethylene oxide), poly (ethylene glycol), and hyaluronic acid will passivate the solid surface and play the roles of additives in industrial lubricants. Surfaces passivated by these layers will be opposed to a family of reference biomaterial surfaces at well-defined, molecular-scale separations and the friction forces will be determined. Atomically smooth surfaces will also be studied. Variables will be actual surface area, normal load, adhesion, and frequency of deformation.
