Researchers from IMDEA Materials Institute, Polytechnic University of Madrid, University Rey Juan Carlos, Universidad Politécnica de Madrid (UPM), National Institute for Aerospace Technology (INTA) and Universidad Francisco de Vitoria have developed a multifunctional fiber-reinforced polymer composite that integrates strain sensing, electromagnetic shielding and thermal management within a structural laminate.
The team fabricated laser-induced graphene (LIG) directly on Kevlar fabric via laser photothermal conversion, then incorporated this LIG@Kevlar layer into basalt fiber/biobased epoxy laminates using vacuum infusion, a process compatible with industrial-scale manufacturing. This in-situ conversion strategy avoids separate LIG films or transfer steps, helping to maintain interlaminar integrity and eliminating foreign interfaces that could otherwise weaken the composite.
Electrical measurements showed frequency-independent AC/DC conductivity, with sheet conductance rising from 0.004 S/□ to 0.014 S/□ as laser power increased from 20% to 27%. Mechanically, the laminate retained its structural performance, with tensile modulus increasing from 20.4 GPa to 22.0 GPa and only minor reductions in tensile strength, indicating that multifunctionality is achieved without sacrificing stiffness.
The LIG network provides piezoresistive strain sensing with gauge factors up to approximately 1.02, enabling in-situ monitoring of deformation. At the same time, the conductive layer delivers electromagnetic interference (EMI) shielding in the 0.5–5 GHz band, and supports Joule heating functionalities: under low applied voltage, the surface temperature exceeds 50 °C, allowing effective de-icing at −40 °C within 5 minutes.
Overall, this work demonstrates a scalable route to embed electrical, sensing and thermal functionalities directly into non-carbon fiber composites while preserving their structural integrity, opening opportunities in sectors such as electric mobility and wind energy.
