Fuzzy Fiber Sensors for Structural Composite Health Monitoring (Preprint)

Abstract : Fibers used in composite materials can be coated with carbon nanotubes in a configuration where the nanotubes grow radially away from the fiber surface. In this configuration, the fiber takes on a fuzzy appearance. The network of nanotubes acts as a somewhat conductive coating. This research was a preliminary exploration of fuzzy fiber response to mechanical stimulus, with an eventual goal of incorporation into advanced composite structures, where they would be used to sense strain or crack growth. The resistance change of the fuzzy fibers to applied strain was measured in the following configurations: individual fiber, fiber tow, tow in matrix, and tow in laminated composite. Use as a strain sensor appears promising, where fuzzy fiber tows could be incorporated as a small percentage of a structure. In this arrangement they are non-parasitic, integral, load carrying members of the structure, with the potential to provide widearea detection of damage.