Lotus Bioinspired Superhydrophobic, Self-Cleaning Surfaces from Hierarchically Assembled Templates

The super hydrophobic, self-cleaning properties of natural species derive from the fine hierarchical topography evolved on their surfaces. Hierarchical architectures which are function-mimetic of the lotus leaf are here described and created from multi-scale hierarchical assembled templates. The first level of hierarchy was a micromachined dome structure template and the second level of hierarchy was added by layering a thin nanoporous membrane such as porous anodized alumina or an ion track etch membrane. The assembled templates were nanoimprinted by a single step process on thermoplastic films. The wetting angle of the surfaces reached a value of 160 degrees and the self-cleaning behavior was observed. The superhydrophobic behavior remained over 1 year after fabrication, which demonstrates the stability of these polymeric self-cleaning topographies. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B. Polym. Phys. 2014, 52, 603-609