Raman-Electromechanical coupling of SWCNT coated single glass fibers for sensor applications

This paper reports the development of health monitoring sensors based on single glass fibers coated with single-walled carbon nanotubes (SWCNT)/epoxy nanocomposites. Uniform coatings with varying SWCNT concentrations via a dip coating method are found to significantly increase the electrical and mechanical properties of single glass fibers. The strain-induced Raman G' band shift and electrical resistance change are successfully coupled for the first time for in situ sensing of deformation and damage in composite structures. The observed strain distributions from Raman mapping reflect a higher interfacial stress transfer of the coating with a higher CNT content. The linear relationship between the change in electrical resistance and fiber strain due to the modification of conductive networks within the coating clearly demonstrates that the CNT coated glass fibers can serve as strain sensor to monitor the deformation and damage to composite structures.