Author(s):
Machado, Beatriz S. ; Morais, Maria ; Pinheiro, Tomás ; Deuermeier, Jonas ; Teixeira, Vasco ; Nunes, Daniela ; Martins, Rodrigo ; Inácio, José M. ; Fortunato, Elvira ; Almeida, Henrique V.
Date: 2025
Persistent ID: http://hdl.handle.net/10362/186776
Origin: Repositório Institucional da UNL
Project/scholarship:
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/LA%2FP%2F0037%2F2020/PT;
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDP%2F50025%2F2020/PT;
info:eu-repo/grantAgreement/FCT/Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017%2F2018) - Financiamento Base/UIDB%2F50025%2F2020/PT;
info:eu-repo/grantAgreement/FCT/3599-PPCDT/2022.08597.PTDC/PT;
info:eu-repo/grantAgreement/FCT/CEEC IND 3ed/2020.01194.CEECIND%2FCP1602%2FCT0002/PT;
info:eu-repo/grantAgreement/EC/H2020/101008701/EU;
info:eu-repo/grantAgreement/FCT/OE/2022.13806.BD/PT;
Subject(s): Agarose-lignin biopolymers; Biocompatible membranes; Cost-effective functional materials; Electroactive materials; Laser-induced graphene (LIG); Sustainable bioelectronics; Electronic, Optical and Magnetic Materials; Electrical and Electronic Engineering
Description
Funding Information: FEDER funds partially financed this work through the COMPETE 2020 Programme and National funds from FCT—Fundação para a Ciência e a Tecnologia, IP, in the scope of Projects LA/P/0037/2020, UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodeling and Nanofabrication—i3N and Project LIGHEART (2022.08597.PTDC), Scientific Employment Stimulus to HV A (2020.01194.CEECIND) and J D (CEECINST/00102/2018), European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement Number 101008701 (EMERGE, H2020-INFRAIA-2020-1) partially supported this work. Also, this work was supported by two PRR Projects: Pacto Bioeconomia Azul (C644915664-00000026) and Fossil to Forrest (C644920945-00000036). M M acknowledges funding from FCT, I P, through the PhD Grant 2022.13806.BD (10.54499/2022.13806.BD). Publisher Copyright: © 2025 The Author(s). Published by IOP Publishing Ltd.
Laser-induced graphene (LIG) is a highly promising material for bioelectronics due to its excellent electrical conductivity, high surface area and biocompatibility. Nevertheless, the functionalization of biocompatible substrates with LIG is essential to propel the use of LIG-derived technologies forward in bioengineering. This study demonstrates the successful fabrication of LIG on agarose-lignin membranes using a single-step CO2 laser process. Membranes with 3 or 5 wt.% agarose, and 0.25 or 0.5 wt.% lignin were characterized for thickness and swelling degree to assess their behavior in a human-mimicking media. The LIG was comprehensively studied, measuring electrical and sheet resistance, and by employing techniques such as Raman spectroscopy, scanning electron microscopy (SEM) coupled with energy-dispersive x-ray spectroscopy (EDS), and x-ray photoelectron spectroscopy (XPS) to evaluate graphitization efficiency and investigate its physicochemical characteristics. Electrical measurements revealed that the lowest sheet resistance achieved was equal to 139 ± 2 Ω sq−1, with lower laser speeds (below 76.2 mm s−1) and higher power settings (above 2.5 W) leading to improved conductivity. SEM analysis revealed a three-dimensional porous structure with pore sizes ranging from nanometers to micrometers, contributing to enhanced electrical conductivity and suitability for bioelectronic applications. EDS mapping further identified carbon, oxygen, and sodium. XPS analysis provided detailed insights into the chemical states of carbon, indicating high-quality graphene formation. The integration of LIG with these flexible, biocompatible membranes highlights their potential for use in bioelectronic devices, including wearable sensors and implantable medical technologies. These findings underscore the potential of agarose-lignin-based LIG as a scalable, eco-friendly platform for future bioelectronic innovations.
