Electromechanical response of semiconducting carbon–polyimide nanocomposite thin films

Electromechanically responsive polymer nanocomposite thin films can provide embedded microscale sensing elements for unobtrusive monitoring of strain, torque and pressure particularly for composite structures. Thin nanocomposite carbon–polyimide films with thicknesses up to 90 μm were produced with carbon contents that yield semiconducting behaviour attributable to distance dependent electron hopping between isolated nanoparticles. The tensile modulus and the strain at break indicated minimum interaction between polymer and nanoparticle surfaces. A decreasing storage modulus with increasing temperature indicated increasing free volume inducing polymer chain motions.