New materials increasingly rely on chemical effects at a very fine scale, sometimes at the atomic level. Understanding how these materials work, how they degrade in service and how we can improve them requires knowledge of how they are put together at this scale. The three-dimensional atom probe (3DAP), first developed at Oxford University, is the only way of seeing the microstructure of materials, atom-by-atom in 3-dimensions. In this way, the 3DAP can be thought of as giving scientists the molecular biology of materials and so helping them understand how materials work. This project aims to greatly improve the existing 3DAP analysis facilities and so provide advanced capabilities for materials analysis at the atomic-scale for scientists in the UK. The instrumentation developed in the project will allow larger volumes of material to be analysed in much shorter times than previously, so that more of the material microstructure can be seen, and also allow semiconductor materials and devices to be studied. Once the new instrumentation is developed, it will be used to study a number of technologically important materials science problems, such as the formation of copper clusters in steels used for the pressure vessels in the reactors on nuclear-powered submarines. The multilayer materials which are being developed for the next generation of read heads in computer hard disks will also be investigated, in order to understand better the way that the structure and the chemistry of these layers control their properties. By linking experiments and modelling at the atomic scale, this project will produce better tools for the design and development of new materials and nanotechnology devices.