Laser-induced graphene for moisture and micro-volume liquid sensing

Fiber-reinforced composites have gained widespread adoption across various industries, including aerospace, automotive, and construction for decades. The growing necessity for monitoring environmental conditions during the storage and service life o f these materials has garnered scientific interest, especially in identifying exposure to harmful liquids that could compromise their structural integrity. Carbon-based sensors provide a unique ability for integration as sensing elements inside composite matrices, presenting an innovative path for multifunctional smart composites. This study presents the fabrication of laser -induced graphene on the surface of resin-infused brown paper, enabling seamless integration into composite structures. The LIG sensor exhibits excellent conductivity of approximately 1.6 kΩ, enabling it to monitor moisture absorption and identify hazardous liquids. LIG produced directly on the surface of composite materials has demonstrated its potential as a cost-effective detector for solvent leakages or moisture uptake in a composite structure, which can serve as a warning system for material degradation.