Eco-Friendly RFID Antennas and Sensors by Laser-Induced Graphene Transfer on Bio-Degradable Substrates

Biodegradable materials offer a promising route toward sustainable electronics, yet their widespread adoption is limited by fabrication complexity and cost. In this work, we present a novel strategy for fabricating transient RFID antennas by transferring Laser-Induced Graphene (LIG) traces on Poly-Vinyl Alcohol (PVA), a water-soluble polymer. The influence of process parameters, i.e., LIG morphology and transfer temperature, on the electrical performance of the transferred conductors is systematically investigated. The results indicate that defocused laser scribing along with with moderate heating (60° C) are the optimal settings to minimize the increase in the sheet resistance down to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3 \Omega/s q$</tex>. The optimized process is applied to fabricate a fully dissolvable UHF RFID dipole antenna operating at 900 MHz. Experimental results confirm good agreement with simulations, yielding a measured realized gain of −18 dB. The device fully dissolves in water within minutes, validating the potential of LIG/PVA systems for biodegradable and transient wireless applications.