Materials Engineering is widely acknowledged as a “hyper-discipline” spanning the fundamental sciences (Physics, Chemistry and Biology) with all of the traditional engineering pursuits (Civil, Electrical, Mechanical, Metallurgical, Nuclear…). A healthy materials engineering program in fapt demands interaction among basic science and technology, all classes of materials, and the intrinsic elements of the field, parochially known as properties, performance, structure (including composition) and synthesis (including processing). Advanced characterization techniques are obviously critical to this integration, and new imaging technologies have accelerated the process of characterizing materials at all relevant length scales, communicating large data sets to practicing engineers, and refining manufacturing methods with image-based technologies. The importance of imaging technologies was forecast by the National Research Council in a highly regarded 1989 report “Material Science & Engineering for the 1990’s: Maintaining Competitiveness in the Age of Materials,” which included prominent mention of all microscopy methods. Since then, the success and challenges associated with imaging technologies have increased dramatically.In the biomaterials field, which is projected to be a $5 billion dollar industry before the year 2000, imaging technologies are most evident. Cross-modal medical imaging (MRI, CAT..) localizes the results of disease or trauma that might be remedied by implantable structures, developed under condition of strict microstructural control, and monitored for degradation products by non-invasive in-situ means. Products include biochemical sensors requiring high spatial resolution characterization of structure and composition, orthopedic prostheses and repairs, sometimes processed to possess pore structures that mimic natural bone, and wound-management devices, including artificial skin composed of bi-layer silicone elastomers and glycosaminoglycan interspersed with collagen. The last of these is especially dependent upon microstructural characterization. Implantable materials systems, such as the cochlear implant for hearing restoration (direct stimulation of the auditory nerve), or heart-assist devices (long fatigue life), require some of the highest standards in materials selection, design, and integration, with the added dimension of biocompatibility. In addition, the irradiation sensitivity of many candidate biomaterials requires strict attention to low-dose imaging methods, rapid scan image acquisition, and sometimes extensive image processing to avoid or circumvent artefacts. Forward-looking projects on fully implantable therapeutic “agents” for medicinal delivery or chelation of toxins and viruses will place even more demands upon our ability to image in-situ functionality.