Equilibrium Droplet Shapes on Micro-Textured Biomimetic Surface

In the arid desert region of Namibia (Africa), there exists a particular type of beetle known as Onymacris unguicularis. Living in a very arid region with very little rainfall, these insects rely on fog to quench their thirst. Previous research including a recent BBC production TV series named as Planet Earth II has shown this amazing behavior of the insects. Their behavior has inspired multiple studies over the years but the fundamental mechanics of fog interaction with their back shell (aka elytron) is yet to be completely understood. The current study is focused on analyzing this liquid-solid interaction using computational tools. A computational analysis of water droplet spreading over a beetle inspired micro-textured model is conducted, supported by live observation of water interaction on a likewise designed 3D printing sample. The target of the research is understanding the effects of such morphology on water collection, in light of capillarity, wetting phenomena and biological signicance. This thesis investigates wetting interfaces, by means of numerical modeling through an open-source Visual BASIC .NET based program. Particularly, the analysis focuses on the air/water interfacial area, which is proved to reduce for droplets deposited on the micro-textured surface, with respect to identical droplets on smooth flat surfaces. Some hypotheses about the influence of such reduction on evaporation are formulated, considering their biological signifcance. Further developments of the analysis are suggested, to achieve a more complete understanding of the phenomenon.