The resistivity response upon stretching of a carbon nanotube/thermoplastic elastomer composite fabricated by a solution process with good nanotube dispersion and low percolation threshold $(p_c\sim 0.35\mathrm{wt}\%)$ is reported. The relationship between resistivity and strain (deformation) shows an exponential relationship with universal, nanotube concentration-independent behavior. The temperature dependence of the resistivity is described by the fluctuation induced tunneling model. The experimental resistivity-strain dependence greater than 5% strain is interpreted in terms of this model by consideration of the gap-width modulation of tunnel junctions. Percolation theory applied to the conductive nanotube network indicates that for less than 5% strain, deformation of the conductive network is the controlling mechanism for changes in resistivity.

• Received 11 April 2007

DOI:https://doi.org/10.1103/PhysRevB.76.195433