Piezoresistive performance characterization of strain sensitive multi-walled carbon nanotube-epoxy nanocomposites

Carbon nanotubes polymer nanocomposites have attracted a significant research, which provide interesting aspects for the realization of cost effective, highly sensitive piezoresistive strain sensors. Here, we report on an extensive piezoresistive performance investigation of multi-walled carbon nanotubes (MWCNTs)/epoxy nanocomposite under uniaxial cyclic tensile and compressive loading in low strain range. Dispersion quality of MWCNTs in the epoxy polymer matrix was monitored by scanning electron microscopy. MWCNTs/epoxy nanocomposite was deposited directly on a glass-reinforced epoxy cantilever beam on the same axis with a commercial metallic strain gauge. The strain sensitive nanocomposite presents high-performance properties, including gauge factor up to 78, good stability of 0.26% for 10 h and durability of -0.08% after cyclic loading and unloading. Furthermore, MWCNTs/epoxy nanocomposites show quite small creep up to 0.26%, fast response and recovery times, low hysteresis under cyclic tensile and compressive loadings and temperature response make the proposed nanocomposites suitable in various potential strain sensor applications including structural health monitoring. (C) 2016 Elsevier B.V. All rights reserved.