Interesting possibilities exist for the scientific design of materials with optimized properties for a diversity of technological applications. For example, the reduction of severe wear and erosion in critical turbine and engine components requires basic studies of intrinsic strengthening, where loads are uniformly transferred across interphase inter-faces. The acheivement of this requires a developed capability for producing selected morphologies on the (i) macro, (ii) micro, and (iii) nanoscale. This involves using a combination of techniques that include the deposition of one, or more, atomic or molecular species in gaseous environments. Recent discoveries suggest, in fact, that it is feasible to design layers where the chemistry and structure at any depth can be pre-selected. Such a capability offers exciting opportunities for forming ‘graded property’ materials, as required in mechanical component and fiber-optic applications. Here, specific radial distributions of chemical species can be used to achieve optimal properties. Another in-triguing possibility is the formation of composite-structure materials, even on the nanoscale, by simultaneous growth of filaments and matrix, using appropriate precur-sors. Thus, metal and polymer matrices may, in principle, be strengthened by various types of fiber and particle distributions. In this approach the basic concept is the syn-thesis of scientifically designed materials for specific technological applications.