Printed Electronics Processing for Structural Integrity (PEPSI)

The development of reliable high-density distributed sensors that can be seamlessly integrated into aircraft structures is essential to the achievement of structural state monitoring for feedback control¡Vi.e., ¡§cognitive aircraft¡¨ technology, where distributed sensor data is algorithmically selected and post-processed in order to provide structural state information. The objective of this research is to continue development of strain sensor and TFT devices which will enhance the capabilities of aircraft by providing the means for measuring static and dynamic state information for structural health and usage monitoring. In Phase I, feasibility of novel organic strain sensors was demonstrated addressing technical barriers such as property mismatch with substrates, interconnect survivability, and device protection. These Wheatstone bridge sensors are small (12 to 60 mil gage length), thin (<1ƒÝ), posses gage factors between 10 to 24, and are designed to match the mechanical properties (such as elastic modulus) of flexible substrates so as to avoid significant sources error associated with property mismatch to flexible materials. Phase II will pursue advanced sensor/TFT development and algorithmic signal processing. A test panel possessing embedded sensor arrays will be fabricated and tested to demonstrate capability for feedback state monitoring.