The NextGen Aeronautics/Penn State team are proposing to extend their Phase I efforts to design and demonstrate an efficient shape memory alloy (SMA) heat engine utilizing improvements in material composition, processing and heat engine design. The proposed SMA heat engine will provide a practical, cost efficient method for powering structural and system health monitoring sensor networks. The primary focus of the proposed Phase II effort is the optimization of the SMA material composition to achieve room temperature phase transition with minimal hysteresis and long fatigue life, extensive material testing over a wide range of operational temperatures, demonstration of scalable SMA material manufacturing methods, development of a fully functional SMA heat engine with high power density, and extensive reliability testing of the system in realistic operational conditions. A comparative evaluation between the developed SMA heat engine and current state-of-the-art thermoelectric generators will also be performed. Successful completion of Phase II effort will result in demonstration of the proposed SMA heat engine in a realistic environment to provide long term, continuous power to integrated sensing systems. We expect to achieve a TRL = 7 for the proposed technology during the Phase II effort and we will develop transition paths with the Army and other DoD partners for further development and maturation of the technology.