Indexed by:期刊论文

Date of Publication:2013-11-01

Journal:MICRO & NANO LETTERS

Included Journals:SCIE、EI、Scopus

Volume:8

Issue:11

Page Number:801-804

ISSN No.:1750-0443

Key Words:electrochemistry; etching; oxidation; hydrophobicity; Al; mathematical model; superhydrophobicity; multiple-level microstructures; natural rice leaf; rice leaves; three-level microstructures; fluoridation; anodic oxidation; electrochemical etching; aluminium substrates; multiple-level biomimetic rice-leaf surfaces; anisotropic sliding

Abstract:The realisation of special anisotropic sliding behaviour of liquids on metal substrates is very important for applications in fluidic control and water directional transportation. Proposed is a method combining lithography assisted electrochemical etching, anodic oxidation and fluoridation to construct the three-level microstructures (macro/micro/nano) of rice leaves on aluminium. Similar to the natural rice leaf, the prepared surface was endowed with multiple-level microstructures and exhibits superhydrophobicity. The measurements show the biomimetic rice-leaf surface has different anisotropic sliding behaviour with water droplets of different volumes. The perpendicular and parallel sliding angles (SAs) of a 4 l water droplet were 6.8 degrees and 2.7 degrees, respectively, the anisotropy was 4.1 degrees, which is comparable to that of a natural rice leaf. A mathematical model is presented to explain the mutational significant anisotropy of SAs (10.2 degrees) when the water droplet was only 2 l. This method is simple and economical, and is believed can be used for the fabrication of large-area biomimetic rice-leaf surfaces on metal.