Harvesting energy from high‐frequency impinging water droplets by a droplet‐based electricity generator

Abstract Harvesting energy from water, in the form of raindrops, river, and ocean waves, is of considerable importance and has potential applications in self‐powered electronic devices and large‐scale energy needs. Recently, the droplet‐based electricity generator has shown an increase by several orders of magnitude in electrical output, overcoming the drawback of traditional droplet‐based device limited by interfacial effects. Despite this exciting result, the output performance of this novel droplet‐based electricity generator is limited by relatively low frequency of impinging droplets owing to the formation of a continuous liquid film at high impact frequency, which might hinder its practical applications. To overcome this challenge, here, we report the design of a superhydrophobic surface based droplet electricity generator, referred to as SHS‐DEG, which can timely shed water droplets from the surface without the formation of liquid film at high impact frequency, and thereby generating enhanced average electrical output. Moreover, our SHS‐DEG exhibits many distinctive advantages over conventional design including robustness, long‐term durability, and power generation stability even in harsh environments. We envision that the ability to harvest electrical energy from water droplets at high impact frequency has promising applications in various energy‐harvesting systems. image