A large-deformation investigation into the electromechanically coupled sensing performances of flexible nanoparticle-reinforced composite stretch sensors

In contrast to the conventional strain sensors under the small-deformation condition, the large-deformation analysis on the flexible nanocomposite-reinforced stretch sensors remains to be investigated. In this research, an extended multi-field coupled homogenization model has been developed to illustrate the nonlinear stretch sensing capacities of flexible nanoparticle-reinforced composite sensors. In this analysis, the stretch-dependent pseudo-moduli and conductivity are chosen as the dual homogenization parameters of current stretch sensing analysis. The predicted resistance change ratio and stretch sensitivity factor are consistent with the experimental data of silver nanoparticle/PDMS nanocomposite sensors over a broad range of stretch loading. The nonlinear stretch sensing performance is attributed to the shape deformation of nanoparticles and significant variation of tunneling distance. The uncovered stretch sensing capacities can provide the directions to optimize flexible nanoparticle-reinforced composite sensors in the area of electronic skin.