Smart materials and Micro/Nano architectonics for water harvesting: From fundamental mechanism to advanced application

The shortage of water resources is a severe challenge that the world faces in the 21st century. By imitating the water harvesting behavior of organisms to obtain water from the atmosphere, it is a feasible way to alleviate the water crisis. The classical wetting theory of solid surfaces, the mechanisms of directional transportation of water droplets and bionic water harvesting principles of different bionic systems are summarized in this review, and the structural characteristics and water harvesting performance of different bionic systems are analyzed. Further, the paper classifies the smart water harvester systematically according to the different types and quantities of imitated organisms, and summarizes the water collection efficiency of different water harvesting methods. Then, this paper summarizes the application status of bionic water harvesting technology in agriculture, industry, and daily life, and prospects for the current shortcomings of smart water harvesting systems and future development trends.