Near-bulge oil meniscus-induced migration and condensation of droplets for water collection: Energy saving, generalization and recyclability

It should be noted that the multifunctional surface is ideal for manipulation droplets to play different roles in various fields, especially for water collection. Here, a unique design scheme, a multibioinspired slippery surface for water collection, is proposed derived from the Namib desert beetle, cactus, aquatic vegetations and Nepenthes, which synergistically combines fog capture, condensation and transportation, indicating better performance than other synthetic surfaces. Without relying on additional energy input or droplet coalescence, this multi-bioinspired slippery surface shows ideal droplet pumping and water collection efficiency. Moreover, the morphology of the triple contact lines is simulated by Surface Evolver, and the state of droplet’s migration is discussed from the perspective of force analysis and energy calculation. The experimental results show that the as-prepared substrate had excellent stability and weather resistance under different circumstance. Compared with the single original Zn sheet, the water collection efficiency of this unique water collection device is increased by about 257.9%. Therefore, this reasonable design strategy and the corresponding theoretical simulation can be applied to a wide range of water harvesting and other fields.