High‐Performance Flexible Graphene Oxide‐Based Moisture‐Enabled Nanogenerator via Multilayer Heterojunction Engineering and Power Management System

Abstract Recently, there has been a surge of interest in nanogenerators within the scientific community because their immense potential for extracting energy from the surrounding environment. A promising approach involves utilizing ambient moisture as an energy source for portable devices. In this study, moisture‐enabled nanogenerators (MENGs) are devised by integrating heterojunctions of graphene oxide (GO) and reduced graphene oxide (rGO). Benefiting from the unique structure, a larger ion concentration gradient is achieved as well as a lower resistance, which leads to enhanced electricity generation. The resulting MENG generates a desirable open‐circuit voltage of 0.76 V and a short‐circuit current density of 73 µA cm −2 with a maximum power density of 15.8 µW cm −2 . Notably, the designed device exhibits a high voltage retention of more than 90% after 3000 bending cycles, suggesting a high potential for flexible applications. Moreover, a large‐scale integrated MENG array is developed by incorporating flexible printed circuit technology and connecting it to a power management system. This integrated system can provide ample energy to operate an electronic ink display and drive a heart rate sensor for health monitoring. The outcomes of this research present a novel framework for advancing next‐generation self‐powered flexible devices, thereby demonstrating significant promise for future wearable electronics.