Surface and interface play an important role in controlling the properties of a broad range of materials. With the recent development of various advanced surface analytical techniques, our understanding of material surfaces and interfaces has been significantly increased, as with our ability to control and even to tailor the surface and interfacial characteristics for specific applications. This is a very broad field which includes material synthesis, structural determination, surface/interface design and modification. In this article, we present some of the important issues concerning the surface and interface control of polymeric biomaterials, conjugated polymers, and carbon nanotubes for biomedical and optoelectronic applications and describe the use of X-ray photoelectron spectroscopy (XPS), surface force apparatus (SFA), and neutron reflectometry (NR) for elucidation of the surface and interface structures.