Microdroplet Intaking Spinning Turbine for Active Radiation Fog Harvesting

Atmospheric fog harvesting is a sustainable freshwater solution, but efficiently collecting from low-wind, small-droplet fogs is challenging due to the low inertia of micron-sized droplets. Here, we demonstrate the microdroplet intaking spinning turbine (MIST), a bioinspired active fog collector that actively draws in fog-laden air using rotating samara-like blades. The rotating blades create a stable low-pressure zone that actively draws in fog, increasing incident fog flux by 5.8-fold, and direct droplets into the device's blade contours. An array of biomimetic cactus spines on the blades enhances inertial capture of these microdroplets. Biomimetic drip-tip structures along the blade edges, combined with centrifugal force, enable rapid drainage of collected water, significantly reducing fluid retention. MIST demonstrates collection efficiency one to two orders of magnitude greater than that of existing surfaces, achieving up to 13.8 L m^-2 h^-1 in field tests and 96.8 L m^-2 h^-1 in controlled wind-tunnel tests. MIST device achieved a specific energy efficiency of 86 L kWh^-1 of water, surpassing conventional dehumidification systems under the targeted fog conditions. By actively manipulating airflow, this bioinspired architecture maintains high efficiency across diverse mists under low-wind conditions, demonstrating broad applicability for defogging, outdoor fog harvesting, and viscous oil fume collection.