Hierarchical Structure of Surfaces on Aquatic Species

Structure. There is one major difference, however, between these structures and those found on superhydrophobic surfaces that entrap air within their hierarchical structure—the snail shells trap water molecules within their rough surface. This macroscopic surface roughness, in fact, facilitates the entrapment of water, ensuring that the shells remain in a wet condition. This is a key factor that contributes to their ability to selfclean, in that their usually wetted surface is rarely able to be contaminated (Nishimoto and Bhushan, 2013). 

BarteU, F.E., Bartell, L.S., 1934. Quantitative correlation of interfacial free surface energies. J. Am. Chem. Soc. 56,2205. 

BarthlottjW., Neinhuis, C., 1997. Purity of the sacred lotus, or escape from contamination in biological surfaces. Planta 202,1. 

Barthlott,W., Neinhuis, C., Cutler, D., Ditsch, E, Meusel, I.,Theisen, I.,WUhelmi, H., 1998. 

Bechert, D.W., Bruse, M., Hage,W.,Van Der Hoeven, J.G.T., Hoppe, G., 1997. Experiments on drag-reducing surfaces and their optimization with an adjustable geometry. J. Fluid Mech. 338, 59. 

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