Three‐dimensional Synergistic Strategy for Enhancing Voltage Output of ZnO Hydrovoltaic Devices

Abstract Harvesting energy from low‐frequency disordered raindrop motion has emerged as a promising hydrovoltaic technology for power generation in recent years. Hydrovoltaic devices have garnered widespread attention due to their miniaturization, portability, and substantial power generation potential. However, solid‐liquid interactions in conventional hydrovoltaic devices are limited by the strong screening charge effect of the film structures, which leads to diminished device performance. This work presents a three‐dimensional (3D) synergistic strategy for patterning zinc oxide (ZnO) hydrovoltaic devices to achieve high voltage output. At 50% relative humidity and 20 °C, the single patterned ZnO hydrovoltaic device can continuously generate a pulse voltage exceeding 9 V within 7 h, which is 15 times greater than the 0.6 V of similarly sized ZnO thin‐film device. Further assembling multiple parallel units of patterned ZnO, a power supply is conducted well for a watch demonstration. Moreover, the lightweight (20 g m ⁻² ) and flexible characteristics of the patterned ZnO hydrovoltaic devices make them ideal for large‐area integration and energy collection in practical applications. Thousands of printed and fabricated patterned ZnO devices will be expected to establish surface micro/nanostructure platforms for various energy devices in outdoor environments through extensive series‐parallel connections.