Abstract:

Carbon nanotube yarns are micron-size fibers that contain thousands of intertwined carbon nanotubes in their cross sections and exhibit piezoresistance characteristics that can be tapped for sensing purposes. Carbon nanotube yarn sensors can be integrated in polymeric and composite materials and measure strain through resistance measurements without adding weight or altering the integrity of the host material. This paper presents the concept and configurations of novel strain gauge sensors comprised of carbon nanotube yarn. A modeling effort consisting of parametric optimization schemes is considered to maximize the sensor’ sensitivity to mechanical loading. The effect of several parameters on the strain gauge sensitivity are discussed including the angle, separation and arrangement of the carbon nanotube yarns within the sensor, the component and magnitude of the applied mechanical stress, and the dimensions and shape of the sensor among others. The innovative fabrication of these strain gauge sensors is also discussed in the context of their use in the surface or the interior of polymeric or laminated composite materials. Current research and development efforts of these strain gauge sensors and carbon nanotube yarn sensors for damage detection are presented including aims and challenges.