In-situ Sensing for Multi-Functional Structures

Aurora has developed a method to directly embed conductive fibers and dielectric layers into a carbon fiber-reinforced polymer (CFRP) structure. To date we've been using this method to embed wiring harnesses and heaters into structures. The proposed innovation leverages our success with embedded wiring, to embed strain gages and thermocouples. The resulting innovation yields CFRP structures with multiple functionalities: 1) transmitting electrical power 2) transmitting electrical signals 3) heating 4) sensing strain due to loading 5) sensing residual strain due to manufacturing 6) sensing crack propagation 7) sensing temperature The innovation is enabled by a novel combination of materials within a shared manufacturing process. The material combination makes use of common carbon fibers that are conductive and demonstrate peizoresitive properties. By layering and arranging these materials in a novel manner, the functionalities listed above can be realized. Given that these sensing materials are in-situ (i.e. the materials are all fiber based and share a common matrix material) structural integrity is not compromised and the sensors are more likely to survive a lifetime of cyclic loading. Additionally, because the sensory materials and conductors are all fiber-based, automated manufacturing techniques (e.g. automated fiber placement) can be utilized to reduce manufacturing costs. The embedded technologies, in combination with Aurora's self- aware aircraft tools, promise to reduce weight, increase performance, and life expectancy of aircraft.