Active Monitoring of COmposite Structures through Embedded Synthetic Fiber Sensor

Modern and future automobiles increasingly incorporate composite materials in the automobiles’ structures to make them lighter and more fuel-efficient. Monitoring these structures is critical for their safe usage, especially when used in critical parts such as battery housing or as part of the vehicle’s outer body structure, where they are exposed to extreme conditions and potential mechanical impacts. Methods to monitor thermo-mechanical changes of these composite materials will help provide early warning of any imminent failures and enable precautionary measures to be taken to ensure safety. New technology based on novel conductive smart fibers that are sensitive to temperature and mechanical impacts and are highly compatible with composite structure manufacturing process will be developed to sense and record mechanical and thermal abnormalities in vehicle’s composite structures. The smart fiber is an electrically conductive bicomponent textile-grade fiber that changes the electrical resistivity under varying thermal and mechanical conditions while adding mechanical strength to the host material, making it a multifunctional technology. The synthetic smart fiber is a co-extruded polymer filament with a dielectric sheath and an electrically conductive core. Capable of being spun into a yarn, the smart fiber can be either woven into composite materials or laid out between carbon fiber layers to sense temperature and mechanical impacts by directly monitoring the changes to the filament’s electrical resistive and reactive properties. Phase I development will focus on formulating the composition of the polymer matrix of the smart fibers for the sensing of temperature and mechanical impacts as well as heat dissipation facilitated by the fibers. The smart fibers will be embedded in different layers within the composite structures and the sensor’s response to different modes of failure (impact, thermal cycling, etc.) will be tested. Analyzing the sensor data for abnormalities by using machine learning algorithms will provide warnings for structural failures. The proposed multifunction smart fiber sensor can be seamlessly embedded into any type of composite structures. The smartphone-sized low-power reader electronics and low cost of the sensor fibers will enable fast commercialization in the automotive and space industries.