Robust and Durable Biodegradable Polymer-Based Triboelectric Nanogenerators Enabled by Trace Melanin-Like Nanoparticles

Abstract

Sustainable energy harvesting in wearable triboelectric nanogenerators (TENGs) demands materials that are both high-performing and eco-friendly. Biodegradable polymer blends emerge as a promising option, offering not only environmental benefits but also good mechanical and triboelectric properties. Yet, phase separation remains a major challenge. This study demonstrates that biomass-derived melanin-like nanoparticles (MNPs) function as an eco-friendly compatibilizer, enhancing phase compatibility in PLA/PBS blends. The addition of merely 0.4 wt.% MNPs led to a 10.4-fold increase in elongation at break, a 13.2-fold increase in tensile toughness, and a 1.1-fold rise in tensile strength. Triboelectric performance also improved significantly, with the charge density increasing by 1.78 times, reaching 414.88 μC/m². Under UV exposure, the MNP-modified blends exhibited strong stability, with only a 9% reduction in performance after 7 days. MNPs promoted a controlled degradation rate that can accelerate under certain conditions, ensuring the composite remains stable during regular use and maintains biocompatibility. When used in wearable motion sensors, M-TENGs displayed consistent and strong signals, accurately detecting a range of human movements, including walking, jogging, and jumping. These outcomes identify MNPs as an innovative and sustainable strategy for boosting the mechanical, triboelectric, and environmental performance of biodegradable polymer-based triboelectric materials, enabling their use in durable and eco-friendly wearable TENGs.