title: A gecko skin micro/nano structure - A low adhesion, superhydrophobic, anti-wetting, self-cleaning, biocompatible, antibacterial surface.
abstract: Geckos, and specifically their feet, have attracted significant attention in recent times with the focus centred around their remarkable adhesional properties. Little attention however has been dedicated to the other remaining regions of the lizard body. In this paper we present preliminary investigations into a number of notable interfacial properties of the gecko skin focusing on solid and aqueous interactions. We show that the skin of the box-patterned gecko (Lucasium sp.) consists of dome shaped scales arranged in a hexagonal patterning. The scales comprise of spinules (hairs), from several hundred nanometres to several microns in length, with a sub-micron spacing and a small radius of curvature typically from 10 to 20 nm. This micro and nano structure of the skin exhibited ultralow adhesion with contaminating particles. The topography also provides a superhydrophobic, anti-wetting barrier which can self clean by the action of low velocity rolling or impacting droplets of various size ranges from microns to several millimetres. Water droplets which are sufficiently small (10-100 μm) can easily access valleys between the scales for efficient self-cleaning and due to their dimensions can self-propel off the surface enhancing their mobility and cleaning effect. In addition, we demonstrate that the gecko skin has an antibacterial action where Gram-negative bacteria (Porphyromonas gingivalis) are killed when exposed to the surface however eukaryotic cell compatibility (with human stem cells) is demonstrated. The multifunctional features of the gecko skin provide a potential natural template for man-made applications where specific control of liquid, solid and biological contacts is required.
authors.affiliation: School of Science and Engineering, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia. Electronic address: gwatson1@usc.edu.au.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Watson
authors.affiliation: Department of Oral Biosciences, Faculty of Dentistry, University of Hong Kong, The Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong.
authors.forename: David W
authors.initials: DW
authors.lastname: Green
authors.affiliation: School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia.
authors.forename: Lin
authors.initials: L
authors.lastname: Schwarzkopf
authors.affiliation: Department of Oral Biosciences, Faculty of Dentistry, University of Hong Kong, The Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Centre for Microscopy & Microanalysis and the School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
authors.forename: Bronwen W
authors.initials: BW
authors.lastname: Cribb
authors.affiliation: The University of Oxford, Begbroke Science Park, Sandy Lane, Yarnton OX5 1PF, UK.
authors.forename: Sverre
authors.initials: S
authors.lastname: Myhra
authors.affiliation: School of Science and Engineering, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia. Electronic address: jolanta.watson@griffith.edu.au.
authors.forename: Jolanta A
authors.initials: JA
authors.lastname: Watson
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001672:Biocompatible Materials; D057927:Hydrophobic and Hydrophilic Interactions; D008116:Lizards; D013499:Surface Properties; D017155:Wettability
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials
keywords: Adhesion; Anti-wetting; Antibacterial; Biocompatible; Gecko