High-Performance Biocompatible Moisture-Enabled Nanogenerators Using a Gelatin-SnS2 Composite for Sustainable Energy Harvesting

ACS Appl Mater Interfaces. 2025 Jul 14. doi: 10.1021/acsami.5c04325. Online ahead of print.

Abstract

The rising global energy demand and environmental concerns necessitate the development of sustainable energy-harvesting technologies. Among these, moisture-enabled nanogenerators (MEGs) have emerged as a promising solution, harnessing ubiquitous moisture in the environment to generate clean energy. MEGs operate through diffusion-induced micro- or nanofluidic proton transport between two electrodes; however, existing devices often produce only transient outputs. Addressing this limitation, we developed a biocompatible MEG utilizing a quasi-solid gelatin matrix and a 2D SnS2-based composite, delivering a continuous open-circuit voltage of 0.95 V, a short-circuit current of 241.6 μA, and a power density of approximately 358.6 μW/cm2 at 90% relative humidity (RH). Furthermore, the device demonstrates the capability to generate electricity from human breath and hand proximity, opening avenues for self-powered medical devices. The fast response of humidity makes it suitable for health monitoring applications in conditions such as sleep apnea, asthma, and respiratory disorders. A comparative performance analysis with other protein/2D material-based MEGs highlights the superior efficiency and stability of our device. The integration of gelatin with SnS2 enhances energy output while maintaining environmental friendliness, paving the way for next-generation autonomous electronics. This study underscores the potential of biocompatible MEGs in addressing energy challenges through innovative and sustainable approaches.

Keywords: gelatin-SnS2 composites; moisture-enabled nanogenerators; proton diffusion; self-powered medical devices; sustainable energy harvesting.