Description: This Phase II Expanded (Ph II-X) effort will build on CRG’s base Phase II effort that has achieved technology readiness level 5 and compliments NASA’s Advanced Air Transport Technology (AATT) project goals to improve structural efficiency, safety, and environmental compatibility of future aircraft. CRG’s proposes to develop a strain sensor utilizing a stitched CNT yarn network within a composite laminate. The ability to measure strain within critical composite airframe structures during flight demonstrates multifunctionality of the CNT yarns and will lead to improved air vehicle safety. At the conclusion of the Ph II-X effort, a CNT yarn strain sensor and data acquisition system will be demonstrated at a technology readiness level (TRL) of 5 under load cases of interest. Beyond the efforts in the base Phase II project, this Ph II-X will inform the piezo-resistive behavior of the CNT yarns stitched within a composite, develop a strain data collection system, verify the performance of the CNT yarn strain sensor under multiple load cases at the coupon scale, and outline a path to transitioning the stitched CNT strain sensors within composite aircraft components. Successful completion of the Ph II-X effort will result in a stitched CNT yarn strain sensor and measurement system that is ready for integration within ground or test flight demonstration articles for Phase III transition opportunities (e.g. Boeing ecoDemonstrator Program) .

Benefits: Advanced Air Transport Technology (AATT) Project Advanced Air Vehicle Program (AAVP) Pressure Vessels Subsonic and Supersonic Vehicle Systems High-temperature Structures (Carbon-Carbon)

Commercial Transport and Cargo Aircraft DoD Fighters, Bombers, Cargo, Transport, and ISR Aircraft Hypersonics, Missiles, Spacecraft, and Satellites Automotive, Marine, and Civil Infrastructure