Figure 4.

In vitro absorption and evaporation of water droplet on the surface of cactus-inspired model. (A) Schematic of the experimental setup. Three different types of meshes with different wettability were tested. A water droplet with 2 μL volume was dropped on the mesh. Temporal variations in the shape and absorption process of the water droplet were continously observed on the (B) hydrophobic mesh and (C) the plasma-treated hydrophobic mesh. (i) At the initial state, the droplet is dropped on the mesh. With time, the droplet is evaporated and permeated into the mesh. Images of the water droplet (ii) just before and (iii) after the water absorption. (D) Comparision of normalized volumes of absorbed water droplet on the different types of meshes. (E) Temporal variations of normalized weight of the Petri dish containing the three meshes. Error bars indicate standard deviation (n = 2).