Highly efficient fluid energy harvesting <i>via</i> flow guiding rapid charge transfer for advanced nanogenerators

Efficient collection of fluid kinetic energy is a key technology for developing clean and sustainable energy sources. Based on solid-liquid contact electrification and electrostatic induction, droplet electricity generators (DEGs) have attracted extensive attention in recent years. Despite great progress in this field, how to achieve controllable droplet motion during solid-liquid triboelectric processes and thereby enabling efficient energy conversion of DEGs remains a challenge. Herein, we propose a strategy for efficient fluid energy harvesting <i>via</i> rapid charge transfer using a flow guiding droplet electricity generator, <i>i.e.</i>, a droplet electricity generator with a fluorinated microstructured array surface (FMA-DEG). The introduction of the microstructured array not only significantly increases the solid-liquid contact points, but also directionally guides the dynamic droplet friction process and quickly achieves the wetting-dewetting behavior regulation, which accelerates the contact separation process, facilitates rapid charge transfer and eventually improves the energy conversion efficiency. The results of diverse demonstration prototypes confirm the use of FMA-DEG for humidity detection, breathing monitoring and enhanced bubble energy harvesting, <i>etc.</i> Thus, this work provides a new route for highly efficient fluid energy harvesting by designing microstructured interfaces, showing great potential in wearable devices, self-powered sensing and fluid analysis.