All Weather‐Usable Wearable Dual Energy Harvester for Outdoor Sustainable Operation

ABSTRACT Sustainable power sources for outdoor wearable electronics are essential for the continuous operation of wearable devices. However, the current lack of engineering design that can harvest energy regardless of weather conditions presents a significant challenge. In this regard, this study introduces a wearable, breathable all‐weather usable dual energy harvester (AWuDEH) that can seamlessly generate electrical energy regardless of weather conditions. In this study, the AWuDEH integrated with the thermoelectric generator and the droplet‐based electricity generator is demonstrated. The AWuDEH, especially engineered with a bi‐functional top substrate for radiative cooling and electrification, achieves sustainable energy harvesting outdoors, thereby addressing the conventional challenge associated with the necessity for separate energy harvesters tailored to outdoor usage contingent on weather conditions. The device reaches a maximum power output of 14.6 µW cm −2 under simulated sunny conditions and generates a much more enhanced thermoelectric power of 74.78 µW cm −2 and a droplet‐based electric power of 256.25 mW m −2 in rainy conditions. As proof, this study developed self‐powered wearable electronics capable of acquiring physiological signals in simulated outdoor scenarios. This study presents a promising advancement in wearable technology, offering a potent solution for sustainable energy harvesting independent of weather conditions.