Laser-induced graphene electrodes with tunable super-hydrophobicity and conductivity: A parametric study for scalable fabrication

Graphene electrodes are integral to advancing energy storage, flexible electronics, and sensor technologies. Incorporating superhydrophobic properties into such electrodes can further enhance performance by improving corrosion resistance, reducing interfacial losses, and increasing durability. This study presents a novel, single-step fabrication of superhydrophobic and highly conductive laser-induced graphene (LIG) electrodes using a low-cost 445 nm diode laser. Compared to the more commonly used CO₂ lasers, the diode laser offers significant advantages, including lower cost, compact size, and higher energy efficiency, making the process more accessible and scalable for practical applications. The graphene layers were directly patterned on polyimide films, and their properties were optimized by varying laser power and scanning velocity. Comprehensive characterization via four-point probe measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle analysis confirmed the successful formation of conductive graphene with superhydrophobic morphology. Optimal parameters of 1 W laser power and 6 mm/s scanning velocity produced an electrode with a low sheet resistance of ∼50 Ω and a static contact angle exceeding 150°, achieving superhydrophobicity without additional chemical treatment. The resulting electrodes exhibit excellent stability and reproducibility. During a 7-day ambient aging test, the electrical resistance remained stable at ∼50 Ω, and the surface retained strong hydrophobic character (contact angle ∼131°) with a low sliding angle (∼11°), confirming robustness for sustained operation. This work demonstrates a cost-effective and efficient route to multifunctional electrodes, with direct applications in underwater sensing, corrosion-resistant flexible electronics, self-cleaning interfaces, and biofouling-resistant marine devices. • Single-step, cost effective fabrication of conductive superhydrophobic surfaces. • Wavelength-specific effects enabling finer control over graphene morphology. • Potential for wearable devices, anti-corrosive surfaces and underwater sensors.