Iron Oxide Embedded Laser-Induced Graphene for High Sensitivity and Durable Strain Sensors in Wearable Applications

Abstract

Graphene-based flexible strain sensors have attracted significant interest for next-generation wearable electronics due to their exceptional electromechanical properties. Their sensitivity can be further enhanced by incorporating metal and metal oxide nanoparticles into the graphene framework. However, existing fabrication approaches are often complex and expensive. We present a laser-assisted, scalable, and cost-effective strategy to construct 3D porous graphene architectures uniformly embedded with iron oxide nanoparticles. The process involves fiber laser irradiation of iron-nitrate-treated laser-induced graphene (LIG), which yields hierarchical nanostructures with a markedly enhanced piezoresistive response. The resulting sensors exhibit an ultrahigh gauge factor (GF = 635), fast response time (40 ms), excellent mechanical durability (over 5000 cycles), and a broad sensing range (up to 11%). Structural characterization confirms the effective and homogeneous integration of iron oxide nanoparticles within the graphene matrix. These results highlight the potential of this laser-fabricated nanocomposite platform for high-performance, flexible sensing systems in wearable and soft robotic applications. © 2025 The Author(s). Advanced Materials Interfaces published by Wiley-VCH GmbH.