Microelectromechanical systems (MEMS) have transitioned from a technology niche to a role of major industrial significance. The worldwide market for MEMS is now approximately $10 billion, and the total value of systems enabled by MEMS is several orders of magnitude higher than this figure. As the market has grown, the material and process sets have broadened and departed from their semiconductor roots. In addition to engineering materials, there is now great interest in integrating multifunctional nanomaterials, smart materials and biomaterials within MEMS/NEMS to enhance functionality, performance and reliability. The opportunities created by this integration have generated a vibrant research community working on new materials and processes. This book reflects the breadth of topics currently under investigation in the field. Novel materials and accompanying processes are discussed, as are more conventional materials and processes. Consistent themes are the need for accurate material property assessment at the relevant length scales and for suitable metrology tools to support the introduction of new materials.