Theoretical consideration and experimental investigation of existence of energy barrier in wetting of multi-pillar surface

自然界中可以看到各种各样的表面，如植物、昆虫和生物。这些表面通常覆盖着毛发和有机化合物的薄片。其中，在荷叶上观察到的荷花效应是众所周知的表面函数的典型例子。荷叶完全排斥水分，通过水滴的滚动清洁荷叶表面（自洁）。另一方面，人们可以在早期发现这种表面具有超拒水性，但是，这些表面由于扰动和时间的推移而表现出润湿性。这在物理上意味着在可湿和可湿状态之间存在能量屏障。在本研究中，我们从理论和实验上研究了多柱表面作为植物、昆虫和生物的模型表面的润湿现象，以研究能量势垒。

Various surfaces can be seen in nature such as plants, insects and living matter. These surfaces are usually covered by hairs and flakes of organic compounds. Among them, lotus effect observed on lotus leave is well-known as a typical example of surface functions. Lotus leaves repel water completely and its surface is cleaned by rolling of water droplets (self-cleaning). On the other hand, one can find super-water-repellency on such surfaces in early stage, but, these show wettability by perturbation and passage of time. This physically means that the existence of an energy barrier between dewettable and wettable states. In this study, we have theoretically and experimentally studied wetting phenomena of multi-pillar surfaces as model surface of plants, insects and living matter to study the energy barrier.