High‐Efficiency Single‐Droplet Energy Harvester for Self‐Sustainable Environmental Intelligent Networks

Abstract Our community is still far away from achieving self‐sustainable ambient intelligence, since it calls for rational energy layouts to satisfy the ubiquitous power demands from diverse terminal products. Harnessing energy directly from the surroundings thus provides ideal solutions. The majority of existing environmental harvesters rely on sophisticated procedures and expensive or toxic materials; while others attempt to streamline the complexity at the cost of compromising performance. This entails transducers that exhibit superb outputs and also employ cost‐effective, even recycled materials and straightforward protocols to render ubiquitous deployments. Here, a high‐efficiency droplet energy nanogenerator (DENG) is devised to satisfy all the requirements. The DENG is fabricated by directly coating a composite layer on a recycled digital video disk surface. It achieves superb electricity generation from one droplet, with an output voltage of >190 V at an instantaneous power density of 65 W m −2 , and an energy conversion efficiency of 3.60%. Diverse demonstrations confirm the applicability of the DENG in environmental networks, encompassing self‐sustainable “on plants” sensing systems, smart building windows, and remote environmental monitoring platforms. In light of these superiorities, it is believed that the DENG may open up new alternative routes for future energy strategies.