Explosive growth in the fiber-optic telecommunications infrastructure during the past decade has driven noteworthy advances in thin-film-based optical interference filter technology. In particular, the widespread deployment of wavelength-division multiplexing (WDM), a means of increasing the communication capacity of an optical fiber by utilizing more than one wavelength of light, has motivated significant improvements in bandpass filter performance. A common requirement is for filters that combine or separate wavelengths spaced 100 GHz (0.8 nm) apart. The foundation for these recent breakthroughs has been laid by the development of optical coating technology over the past century. This article reviews the materials and processes used in the production of thin-film-based optical communications filters.

This review examines textile fibers and fabrics in the context of their interaction with various forms of energy, such as electromagnetic (photolytic), electrical, magnetic, thermal, chemical, and mechanical. This interaction can involve conversion, storage, or management of energy. Examples are described suggesting some new material configurations that could be incorporated into textiles to create special energy-interactive textile (EITX) structures. Areas discussed are the management of electron flow (electrical resistivity) and the absorption of mechanical energy in textile fibers and fabrics. Surface resistance studies on carbon nanotubes and conductive carbon-black-filled films of poly(methyl methacrylate) (PMMA) and paraffin wax show that the electrical conductivity of these materials depends upon the matrix material type and the amount of charge-carrying particles in the matrix. PMMA films filled with carbon nanotubes are found to be more electrically conductive than matrices filled with conductive carbon black. Mechanical-energy interactions of flocked textile surfaces show that in compression, they exhibit unique, gradual load-deflection behavior. This effect should be useful in applications requiring impact-energy absorption. Finally, the functional steps in an integrated energy-interactive textile system are discussed.

Carbon nitride is an emerging material for wear-resistant coatings. The fullerene-like CNx compounds generally exhibit extreme elasticity in combination with a low work of indentation hardness. Yet CNx shows a low-to-moderate resistance to penetration, depending on deposition conditions. Since the deformation energy is predominantly stored elastically, the material possesses an extremely resilient character. This new class of materials consists of sp2-coordinated basal planes that are buckled from the incorporation of pentagons and cross-linked at sp3-hybridized C sites, both of which are caused by structural incorporation of nitrogen. Carbon nitride thus deforms elastically due to bending of the structural units. The orientation, radius of curvature of the basal planes, and the degree of cross-linking between them defines the structure and properties of the material. Due to the unique deformation behavior, the hardness requires special care to assess, but can be very high for films with a large degree of cross-linking. This article is a review of the research on CNx films depositedby reactive magnetron sputtering, with examples from our recent work. The findings are significant for the design of fracture-tough materials.

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.

A number of different types of adhesives are used in the assembly of electronic components and devices. This article provides an overview of such adhesives that also have another job–they work at conducting electricity or heat. The resins or binders in these adhesives range from thermosetting to pressure-sensitive. Conductivity is obtained by the judicious choice of filler. For electrically conducting adhesives, the fillers range from silver flake to silver-coated fibers. For thermally conducting adhesives, the fillers range from aluminum oxide to boron nitride. We also discuss a specific type of electrically conducting adhesive–the z-axis film adhesive. In these adhesives, particles are oriented in such a fashion that allows conduction in the direction perpendicular to the adhesive, but not in the plane of the adhesive.

The trend for microelectronic devices has historically been, and will continue to be, toward a smaller feature size, faster speeds, more complexity, higher power, and lower cost. The driving force behind these advances has traditionally been microprocessors. With the tremendous growth of wireless telecommunications, rf applications are beginning to drive many areas of microelectronics that traditionally were led by developments in microprocessors. An increasingly dominant factor in rf microelectronics is electronic packaging, and the materials needed to create the package, because the package materials strongly affect the performance of the electronics. Many challenges remain for the packaging of microprocessors as well. These challenges include increased speed, the number of input/output interconnects, decreased pitch, and decreased cost. This article highlights the key issues facing the packaging of high-performance digital and rf electronics.