CNT enabled fabric sensors for highly sensitive and large-area monitoring of polymeric composites

The next-generation of hierarchical composites needs to have built-in functionality to continually monitor and diagnose their own health states. This paper presents a novel strategy for in-situ monitoring the processing stages of composites by co-braiding CNT-enabled fiber sensors into the reinforcing fiber fabrics. This would tremendously improve present methods that excessively focus on detecting mechanical deformations and cracks. The CNT enabled smart fabrics, fabricated by a cost-effective and scalable method, are highly sensitive to monitor and quantify various events of composite processing including resin infusion, onset of crosslinking, gel time, degree and rate of curing. By varying curing temperature and resin formulation, the clear trends derived from systematic statistics confirm the reliability and accuracy of the method. More importantly, localized processing information of composites can be achieved in real time upon wisely configuring the smart fabrics with a scalable sensor network. In addition, the smart fabrics which are readily and non-invasively integrated into composites can provide lifelong structural health monitoring of the composites, including detection of deformations and cracks.