High efficiency and fog flow direction-independent fog collector with pentagram bulges

Water scarcity is a global problem that has a great impact on people's production and life, and how to get as much fresh water as possible is an urgent problem to be solved nowadays. Inspired by umbrellas, corrugated paper, and desert beetles, this paper presents an efficient fog collector that combines macrostructures and surface wettability gradients. This fog collector has an overall inverted umbrella-like structure and a corrugated structure on the umbrella surface. Pentagram-shaped hydrophilic bulges are evenly distributed on the umbrella surface. When the number of hydrophilic bulges was 176 and the lower prong of the corrugated structure was at an angle of 30 degrees to the horizontal, the fog collector reached an optimum fog collection efficiency of 231.5 % of the original copper sheet. In addition, sand impact tests and UV resistance tests were carried out to test the samples for practical application. After a long time of UV irradiation and many sand impacts, the contact angle remained above 150 degrees Moreover, the fog collector not only uses materials which are abundant and easy to obtain, but also simple and efficient to prepare, which provides a new idea for the design of high-efficiency fog collectors in the future.