Microelectromechanical Systems (MEMS) is one of the three core enabling technologies within the Microsystems Technology Office (MTO) of the Defense Advanced Research Projects Agency (DARPA). Together with Photonics and Electronics, MEMS forms the foundation for a broad variety of advanced research projects sponsored by MTO as well as other offices within DARPA. MEMS technology merges the functions of compute, communicate and power together with sense, actuate and control to change completely the way people and machines interact with the physical world. Using an ever-expanding set of fabrication processes and materials, MEMS will provide the advantages of small size, low-power, low-mass, low-cost and high-functionality to integrated electromechanical systems both on the micro as well as on the macro scales. Further, demands for increased performance; reliability, robustness, lifetime, maintainability and capability of military equipment of all kinds can be met by the integration of MEMS into macro devices and systems. In the post-cold-war era, U.S. forces must be able to conduct prompt, sustained, and synchronized operations with our allies in specific situations and with the freedom to operate in all four domains of military engagementsea, land, air, and space. MEMS technology has now been demonstrated in all four domains. The long-term goal of the DARPA MEMS program is to merge information processing with sensing and actuation to realize new systems and strategies to bring co-located perception and control to systems, processes and the environment.