Enhanced Energy Harvesting through Lubricant-Water Interaction on a Superoleophobic Stainless Steel@Cellulose Ester Nanogenerator

Abstract

The growing global population accentuates the critical demand for self-powered smart electronic systems, particularly in sensing and clean energy harvesting. Triboelectric nanogenerators (TENGs) have garnered substantial attention due to their simple design, material adaptability, and efficiency in scavenging ambient low-frequency mechanical energy. Nevertheless, conventional solid-solid TENGs encounter challenges, including diminished output over time, environmental degradation, and mechanical wear. To address these challenges, we developed a lubricant-water triboelectric nanogenerator (LW-TENG) with underwater superoleophobic properties. This design incorporates stainless steel nanoparticles coated on a mixed cellulose ester substrate, and a squalane lubricant droplet to enhance triboelectric performance, achieving an underwater oil contact angle of 159°. The proposed LW-TENG also exhibited an open-circuit voltage (V_OC) of 70 V, a short-circuit current (I_SC) density of ≈2 µA·cm⁻², and a peak power density of ≈84 µW·cm⁻², and long-term microstructural stability. The practical utility of this LW-TENG was validated through a prototype capable of harvesting energy from surface waves, underwater currents, and wind, providing a cost-effective, versatile, and reliable source of electrical power for long-term sensor deployment or emergency scenarios. This work highlights LW-TENG's vast potential in green energy harvesting applications, underpinned by cost-effective manufacturing processes and versatility in deployment.