Robust Conductive Gel-Infused Sponge-based Triboelectric Nanogenerator for Reliable Long-Term Self-Powered Electronics and Wireless Monitoring

Abstract

Conducting hydrogel-based triboelectric nanogenerators (TENGs) have garnered significant interest for their inherent flexibility and biocompatibility. However, their practical deployment is severely constrained by poor mechanical integrity and limited operational lifespans.Addressing these limitations, we report a mechanically robust and long-term stable conductive sponge-based TENG (CS-TENG), engineered via a simple, scalable, and cost-effective approach. The device architecture is based on a sugar-templated polydimethylsiloxane (PDMS) sponge infiltrated with an ionic conductive gel comprising polyvinyl alcohol (PVA) and sodium nitrate (NaNO₃), followed by a controlled thermal curing process. This strategy dramatically enhances the electrical conductivity of the sponge to 649.28 mS/m, which is more than three orders of magnitude higher than that of the untreated structure (185.42 µS/m). The resulting CS-TENG demonstrates exceptional energy harvesting performance, generating a stable output of 61 V and 1.6 µA, with no degradation observed over five months of continuous operation. Moreover, the CS-TENG is capable of directly powering 30 LEDs and seamlessly integrating with wireless platforms to operate 7-segment displays, LCDs, and smartphones. This work introduces a robust design paradigm for the development of durable, high-performance TENGs, offering a promising pathway toward next-generation self-powered, wearable, and multifunctional electronic systems.