Robert W. Balluffi, professor emeritus in the MIT Department of Materials Science and Engineering (DMSE), died Dec. 8 at his home in Ithaca, New York. He was 98 years old. Described by colleagues as the last of an era of materials scientists with a holistic understanding of the field, Balluffi was renowned for both his expertise and publications in a broad range of topics, including crystal defects, solid-state diffusion, and crystalline interfaces. “He represents a way of thinking about materials in general, in all aspects, that is disappearing over time,”…