Numerical investigation of mechanisms affecting the piezoresistive properties of CNT-doped polymers using multi-scale models

Carbon nanotube polymer nanocomposites exhibit conductive behavior due to the formation of conductive nanotube networks inside the polymer. Their electrical resistance is known to vary with strain. Two mechanisms that affect the conductivity and piezoresistive response of CNT nanocomposites are investigated using models at two discrete material scales: (a) nanoscale models to analyze the electromechanical response of carbon nanotubes and (b) nanotube percolation models to investigate the composites electrical resistance at microscale. Numerical studies determine the impact of each mechanism on the macroscopic response of the nanocomposite. Results suggest that the variation of nanotube resistance with strain is the dominant mechanism.