Every day we come into contact with many thousands of manufactured objects that are essential to modern life: the vehicles that we travel in; the clothes that we wear; the machines in our homes and offices; the sport and leisure equipment we use; the computers and phones that we can't live without; and the medical technology that keeps us alive. Everything we see and use is made from materials derived from the earth: metals, polymers, ceramics, semiconductors and composites. To develop the new products and technologies that will make our lives safer, more convenient, more enjoyable and more sustainable we must understand how to make best use of the materials we already have, and how to develop new materials that will meet the demands of the future. Materials Science and Engineering involves the study of the structure, properties and behaviour of all materials, the development of processes to manufacture useful products from them, and research into recycling and environmentally friendly disposal. The basic building block of all matter is the atom and there are 94 different types that occur naturally on earth. These are 'the elements' and include hydrogen, oxygen, carbon, silicon, iron, copper, and aluminium. All materials are made up of these atomic building blocks but differ in their microstructure: the types of atom they contain, the pattern in which the atoms are arranged and the way in which the atoms are joined together. The central concept in Materials Science and Engineering is that the properties and behaviour of