Topology optimization of structures and composite materials is a new and rapidly expanding field of mechanics which now plays an ever-increasing role in most branches of technology, such as aerospace, mechanical, structural, civil and ma- terials engineering, with important implications for energy production as well as building and environmental sciences. It is a truly "high-tech" field which requires advanced computer facilities and computational methods, whilst involving unusual theoretical considerations in pure mathematics. Topology optimization deals with some of the most difficult...