Graphene‐Based Conductive Polymer Composites for Piezoresistive Sensors: Materials, Sensing Mechanisms, and Performance

Abstract

Conductive polymer composites (CPCs) incorporating nano‐carbon fillers have emerged as promising materials for lightweight, flexible, and high‐performance piezoresistive sensors. Owing to their excellent electrical conductivity, mechanical strength, large surface area, and tunable nanostructures, graphene‐based CPCs (G‐CPCs) have demonstrated strong potential for strain, pressure, and deformation sensing. Recent studies have reported high sensitivities with gauge factors ranging from several to over 10 000, broad sensing ranges, fast response/recovery times, and excellent cyclic stability depending on composite design and sensing mechanisms. The piezoresistive behavior of G‐CPCs is primarily governed by conductive network evolution, electron tunneling effects, microcrack propagation, and graphene disconnection/reconnection. Sensor performance is strongly influenced by graphene morphology, nanostructural arrangement, filler content, dispersion quality, polymer matrix selection, and fabrication methods. Various processing strategies, including solution mixing, melt blending, in situ polymerization, coating, electrospinning, and 3D printing, have been explored to optimize conductive pathways and enhance sensing performance. This review systematically summarizes recent progress in the materials design, nanostructural engineering, fabrication, sensing mechanisms, and performance of G‐CPC piezoresistive sensors. Current challenges, including signal stability, hysteresis, durability, and large‐scale manufacturing, are also discussed together with future opportunities for wearable electronics, healthcare monitoring, soft robotics, and intelligent structures.