title: The hydrophobicity of a lotus leaf: a nanomechanical and computational approach.
abstract: The multi-scale microstructure of a lotus leaf is rendered non-wetting by micro-protrusions and nano-hairs present on its surface. The mechanical properties of the surface become important since the water droplet has to be supported on the micro-protrusions without wetting the surface. Current work correlates the non-wetting behavior of the lotus leaf with its mechanical properties (Young's modulus and critical flexing stress) and areal spread of micro-protrusions on the leaf surface. Quasistatic nanoindentation of nano-hairs on the lotus leaf surface has shown a variation of elastic modulus between 359 and 870 MPa, which in turn dictates the critical flexing strength and consequent non-wetting. Computational fluid dynamics modeling is utilized to correlate wetting phenomena with the areal spread of micro-protrusions. A qualitative model is proposed for the way nature has chosen to render the lotus leaf surface non-wetting.
authors: Materials and Metallurgical Engineering, Faculty Building, Indian Institute of Technology Kanpur, Kanpur-208 016, India. kbalani@iitk.ac.in
authors: Kantesh
authors: K
authors: Balani
authors: Ruben Galiano
authors: RG
authors: Batista
authors: Debrupa
authors: D
authors: Lahiri
authors: Arvind
authors: A
authors: Agarwal
mesh_terms: D055119:Elastic Modulus; D057927:Hydrophobic and Hydrophilic Interactions; D000070116:Lotus / Q000737:chemistry* / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D036103:Nanotechnology / Q000379:methods; D018515:Plant Leaves / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D014867:Water