Advances in Laser-Induced Graphene for Flexible Sensors

Laser-induced graphene (LIG) is a porous carbon material produced in situ by direct laser irradiation of carbon-containing precursors. With its three-dimensional porous structure, high electrical conductivity, facile patternability, low cost, and environmentally friendly fabrication, LIG has attracted growing interest for flexible sensing applications. It shows strong potential in wearable electronics, health monitoring, human-machine interaction, environmental sensing, and intelligent robotics. Although LIG-based sensors have demonstrated excellent performance in mechanical and thermal signal detection, a systematic review of their basic materials, formation mechanisms, sensing principles, structural design, performance optimization, and applications remains limited. This review first summarizes the fundamental materials, processing parameters, and formation principles of LIG, and then highlights recent progress in LIG-based strain and temperature sensors, focusing on sensing mechanisms, key performance indicators, optimization strategies, and research status. The main challenges for practical application are also discussed. These include limited material uniformity and fabrication reproducibility, signal coupling and interference in multifunctional devices, and issues of process compatibility and packaging reliability. Future directions for high-performance, integrated, and scalable LIG sensors are then.