Behavioral model for electrical response and strain sensitivity of nanotube-based nanocomposite materials

An algorithm to study the electrical conductivity of nanocomposite layers, made by dispersing nanotubes inside a polymer structure, is proposed. Conduction is modeled by following the path of electric current through the nanotube network within the polymer. Based on this algorithm, a numerical simulator is developed to study the effect of nanoparticles and nanocomposite film dimensions and concentration on the conductance of a nanocomposite resistor. This simulator is also capable of predicting the behavior of nanocomposite resistors under mechanical strain for devices with different parameters. To verify the simulation results, several test devices with different filler concentrations are fabricated from a composite of SU-8 and multiwall carbon nanotubes. The experimental results agree with the performance anticipated by the simulator, as the applied strain and filler concentration are altered independently. The simulator is capable of illustrating the tradeoffs between conductivity, sensitivity, and repeatability and can be used as a powerful tool to pave the path for designing reliable electronic components from nanocomposite materials. (C) 2012 American Vacuum Society. [http://dx.doi.org/10.1116/1.3691654]