The following article is an edited transcript based on the MRS Medalist presentation given by Charles M. Lieber of Harvard University on December 4, 2002, at the Materials Research Society Fall Meeting in Boston. Lieber received the Medal “for controlled synthesis of nanowire and nanotube materials.” This presentation begins with an introduction to the bottom-up paradigm of nanoscience and nanotechnology. The key concepts of this paradigm are explored through studies outlining progress toward meeting the challenge of nanocomputing through the assembly of functional nanowire elements. The richness of the bottom-up paradigm and nanowire building blocks is then illustrated with the development of chemical and biological nanosensors. Finally, the uniqueness of nanowires is exemplified through discussion of the assembly of nanophotonic devices, including the demonstration of multicolor and addressable nanoscale light-emitting diodes, nanowire injection lasers, and assembled arrays of these nanophotonic sources. Challenges and goals for realizing nanotechnologies in the future are discussed in the conclusion.

This article is based on a presentation on organic-based magnets given as part of Symposium X—Frontiers of Materials Research on December 4, 2002, at the 2002 Materials Research Society Fall Meeting in Boston. The advent of organic-based magnets opened the opportunity for tuning magnetic properties by molecular design and the discovery of new phenomena that rely on the internal structure of the molecules that make up these magnets. In the past 18 years, numerous classes of organic-based ferromagnets, ferrimagnets, and spin glasses (spins essentially frozen in place without long-range order) have been reported. These materials have magnetic ordering temperatures ranging from <1 K to above room temperature and demonstrate many of the magnetic properties associated with conventional magnets. This article concentrates on new phenomena that are unique to organic-based magnets. Three of these effects—“high-temperature” light-induced magnetism, spin-polarized magnetic organic semiconductors with the potential for spintronics, and the development of fractal magnetic order—are discussed to illustrate the richness of opportunity in organic-based magnets.

The following article is an edited transcript based on the Von Hippel Award presentation given by Howard K. Birnbaum of the University of Illinois at Urbana-Champaign on December 4, 2002, at the Materials Research Society Fall Meeting in Boston. The award citation states, “Through innovative use of a wide range of novel experimental tools, Howard K. Birnbaum has made seminal contributions to our understanding of intrinsic point defects, hydrogen in metals, and grain-boundary segregation, especially as these effects relate to mechanical properties. He has also stimulated, directed, and influenced interdisciplinary research throughout the materials community.” This presentation summarizes the major phenomenological observations associated with hydrogen effects on fracture and the viable mechanisms that can account for these observations. It is shown that there are three fracture mechanisms that are consistent with the experimental observations and that the operative fracture mechanism depends on the type of system and the conditions under which it is exposed to hydrogen in aggressive environments.

The following article is an edited transcript of a talk presented in Symposium X—Frontiers of Materials Research at the 2002 Materials Research Society Fall Meeting in Boston on December 2, 2002. From Bessemer steel used on the first motorized bicycle in 1871 to sintered aluminum ceramic composites and TiN thin-film coatings used on standard production machines today, motorcycles have been at the forefront of the use of high-performance materials. Thanks to developments in materials technology, relatively inexpensive mass-produced motorcycles are now capable of achieving speeds of >190 mph.

The following article is based on a presentation given as part of Symposium X—Frontiers of Materials Research on December 4, 2002, at the 2002 Materials Research Society Fall Meeting. The cinema is just over 100 years old. From the beginning of motion pictures in the mid-1890s, the materials used for films have been at the heart of cinema technology. The material first used was cellulose nitrate film—unrivaled in its mechanical, physical, and aesthetic qualities, and also dangerously flammable. In the 1950s, cellulose nitrate was replaced, for safety reasons, by cellulose triacetate. Today, polyester film is widely used; nevertheless, the fact remains that the majority of the world's film heritage exists on two main material formats, cellulose nitrate and cellulose triacetate, both of which decay over time. Film archivists are engaged in a race to save historic film footage from being lost forever. Digital technology, now widely used in cinema, does not resolve the issue of the long-term preservation of films because digital formats are still evolving. This article discusses the materials used in motion-picture technology over the years, the mechanisms active in film decomposition, and international efforts to preserve and restore historic films.

There are many advantages that polymeric adhesives can offer compared with the more traditional methods of structural joining such as bolting, brazing, welding, and mechanical fastening, and epoxy adhesives represent the most common type of structural adhesive. When polymerized, epoxy adhesives are amorphous and highly cross-linked materials, and this microstructure results in many useful properties for structural engineering applications, such as a high modulus and failure strength, low creep, and, by careful formulation, good performance at elevated temperatures. However, the structure of such thermosetting adhesives also generally leads to one highly undesirable property: they are relatively brittle materials, with poor resistance to crack initiation and growth. Nevertheless, the incorporation of a second phase of dispersed rubbery particles into the epoxy polymer can greatly increase their toughness without significantly impairing their other desirable engineering properties. Thus, rubber-toughened epoxy adhesives can be used, for example, in applications where very high impact resistance is required for the bonded joint.