Hierarchically structured ZnO nanorod-carbon fiber composites as ultrathin, flexible, highly sensitive triboelectric sensors

Abstract

Design of hierarchical micro-nanostructured zinc oxide nanorods (ZnO NRs) grown on microscale curvature surfaces is suggested for the effective contact area changes between the top and bottom triboelectric layers under mechanical stimuli. The microscale structures of carbon-fiber-reinforced plastics (CFRPs) by means of simple fabrication methods are preserved. By combining micro and nanostructures, they make it possible to be a spacer-free, ultrathin, and highly sensitive triboelectric sensors (TESs). The flexible TES shows a high-pressure sensitivity and bending sensing capability which enables the detection of repeatedly increasing bending because this structure shows the enhanced contact area changes owing to the effective soft spreading layer of flexible CFRPs. In addition, these CFRP-based TESs can detect tensile strains and impact forces, which suggest potential applications as self-powered structural sensors.