Droplet Electricity Generators With Maximized Energy Collection Zone Enabled by Aloe-Inspired Midrib and Cuticle.

Leveraging water as an abundant and continuously available natural resource, droplet electricity generators (DEGs) have gained significant attention for their ability to produce high instantaneous voltages from the simple impact of water droplets. However, conventional DEGs are fundamentally limited by their narrow energy collection zones, confined to regions immediately adjacent to the switch electrode. In nature, Aloe vera overcomes a similar spatial challenge by guiding scarce rainfall toward the root through its midrib-like longitudinal ridge and water-repellent wax-rich cuticle-an integrated water-guiding architecture that transports droplets over long distances with minimal loss. Here, inspired by this mechanism, we introduce a scalable DEG that maximizes the energy collection zone through an artificial droplet-channeling strategy. A midrib-inspired curvilinear geometry induces uni-directional spreading upon impact, while an artificial hydrophobic cuticle composed of a hydrocarbon-based OTS-squalane layer enables smooth, low-retention sliding and robust interfacial stability. These features substantially expand the effective collection zone and yield approximately 236% higher charge output than a conventional DEG, unlocking new opportunities for large-area, distributed, and environmentally adaptive droplet-energy harvesting.