Long polymer chains adsorbed onto solid surfaces are important in a wide range of applications and are relevant to many issues in biology and medicine. Adsorbed polymer layers used widely in the stabilization of colloidal suspensions, for example, are essential to the formulation of paints, coatings, printing inks, drilling needs, and ceramics processing. Adsorbed polymer layers also play a crucial role in many tribological applications such as boundary lubricants.The interfacial behavior of biological macromolecules (such as proteins) plays an important role in biomedical applications as well as in the function of living organisms. The development of biocompatible solid materials that can be used safely and efficiently in vascular and joint prostheses, catheters, artificial-heart valves and whole hearts, cardiac-arrest devices, and hemodialysis cartridges is critically important. In some instances, the adsorption of biological macromolecules onto the artificial material can lead to deleterious effects. For example, many vascular grafts and catheters fail because of thrombotic occlusion initiated by protein adsorption. Protein adsorption is also the initial subprocess that leads to plaque formation in teeth and the fouling of contact lenses. Given the central role of protein adsorption in many physiological systems, and the great benefits that could be derived by designing materials that do not adsorb biological macromolecules, understanding the interfacial behavior of biological polymers is important.The ultimate goal of research in polymer adsorption is to facilitate the manipulation of the properties of adsorbed polymer layers (or polymer-solid interfaces) so that materials with required properties can be fabricated. To take steps toward this goal, understanding how the nature of the polymer, the substrate, and other prevailing conditions (such as the type of solvent) affect the macroscopic properties of the interface is crucial.