Strain sensing mechanism of the fabricated ZnO nanowire-polymer composite strain sensors

The nature of contacts between ZnO semiconductor nanowires and metal pads has attracted great research interests since its impact on enhancing sensitivity of the sensors. Herein, ZnO nanowire arrays were synthesized by a scalable wet chemical method and ZnO nanowire-polymer composite strain sensors were fabricated by utilizing Schottky contact. The electrical transport response to strain was attributed to piezoelectric-effect-induced Schottky barrier height changes at the metal–semiconductor junction under various strained states. When the strain increased from 0% to 0.12%, the average barrier height change increased to 26 meV, inducing sensitive current changes in these strain sensors.