The Materials Research Science and Engineering Center (MRSEC) at the University of Pennsylvania supports a broadly based interdisciplinary research program on complex nanostructures and materials. The research is carried out in four Interdisciplinary Research Groups (IRG) with appropriate seed projects. The IRG on Functional Biomolecular Materials focuses on developing engineering principles for de novo protein design directed towards creation of novel molecular constructs that carry out natural or novel functions with the ultimate goal of producing selectively functionalized modular materials and devices. A second IRG focuses on Carbon Nanotube-Derived Materials and involves the synthesis, assembly and theory of higher-order structures created from single-walled nanotubes. The IRG on Microscale Soft Materials harnesses theoretical and experimental expertise to design and control the self-assembly of new classes of microstructured colloidal systems with tailored optical, mechanical, rheological and storage properties. An IRG of Multifunctional Complex Oxides designs, synthesizes, characterizes and models novel materials that exhibit highly sensitive responses to external magnetic and electrical fields. The MRSEC is also developing innovative methods of instruction. It is linked to the University of Puerto Rico through a Collaborative to Integrate Research and Education. It hosts a significant program for Research Experiences for Undergraduates and it has initiated a program to provide Research Experiences for Teachers. The Center maintains a large set of shared experimental facilities that provide state of the art instrumentation for the entire University, and act as a focal point for graduate education and for knowledge transfer to industry. Participants in the Center include 36 senior investigators, 12 postdoctoral associates, 29 graduate students, 15 undergraduates, and 5 technicians and other support personnel. Professor Michael Klein directs the MRSEC.