Bioinspired Fiber‐Based Moisture Electricity Generator Enabled by Bilayer Hydrogel and MOF Nanosheet Arrays for Self‐Powered Sensing

Abstract

The rapid expansion of wearable and portable electronics has driven increasing demand for fiber‐based moisture electricity generators (FMEGs) capable of operating under ambient conditions. However, achieving efficient ion generation, directional transport, and charge separation simultaneously in fibrous architectures remains challenging due to the absence of coordinated structural design. Here, a hierarchical FMEG is constructed by integrating a bilayer hygroscopic hydrogel with vertically aligned zeolitic imidazolate framework‐L (ZIF‐L) nanosheet arrays via in situ growth and cyclic freeze‐thaw assembly. The bilayer hydrogel establishes coupled water and proton concentration gradients to provide a sustained driving force for ion migration, while the ZIF‐L nanosheet channels enable selective ion transport and improve interfacial charge regulation. Benefiting from this synergistic architecture, the device delivers an open‐circuit voltage of ∼0.9 V and a power density of 82.3 µW cm −2 , while maintaining stable operation over 90 h under ambient conditions. Furthermore, the device can be woven into textiles to power electronic devices and enable self‐powered finger motion encoding and respiration monitoring. This work provides a generalizable structural paradigm for constructing high‐performance FMEGs for wearable energy harvesting and sensing systems.