The hydrophobicity of a lotus leaf: a nanomechanical and computational approach

Nanotechnology. 2009 Jul 29;20(30):305707. doi: 10.1088/0957-4484/20/30/305707. Epub 2009 Jul 8.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Elastic Modulus
  • Hydrophobic and Hydrophilic Interactions
  • Lotus / chemistry*
  • Lotus / physiology
  • Microscopy, Electron, Scanning
  • Models, Biological
  • Nanotechnology / methods
  • Plant Leaves / chemistry*
  • Plant Leaves / physiology
  • Plant Leaves / ultrastructure
  • Water / chemistry*
  • Wettability

Substances

  • Water