3D Nanoconductive Network Based on the Microstructure of Latex Foam for Superior Performance Piezoresistive Sensors

With increasing demand for diversification, miniaturization, and intellectualization of flexible electronic devices, an increasing number of nanomaterials with excellent performance characteristics have been developed. As a result, conductive polymer composites (CPCs), composed of conductive components and insulating polymer matrices, have shown significant potential for use in intelligent sensors. For three-dimensional (3D) piezoresistive sensors with foam structures, the distribution and state changes of the cracks inside the sensors play important roles in their resistance change and sensing ability. In this study, we decorated natural rubber latex foam (NRLF) with polydopamine (PDA) and modified silver nanoparticles (AgNPs) on the NRLF/PDA by in situ reduction to form a three-dimensional conductive network of AgNPs based on a foam structure. The sensing performance of NRLF/PDA/AgNP piezoresistive sensors was investigated, and it was found that the piezoresistive sensor prepared at a low AgNO₃ concentration (5 wt %) exhibited stable resistance change rates at different compression strains. It exhibited a stable trend at different compression rates. The gauge factor (GF) was 81 (working strain: 0–36%). In terms of its good piezoresistive sensing ability, the piezoresistive sensor can accurately monitor human movements such as finger pressing, walking, and jumping.