title: Removal mechanisms of dew via self-propulsion off the gecko skin.
abstract: Condensation resulting in the formation of water films or droplets is an unavoidable process on the cuticle or skin of many organisms. This process generally occurs under humid conditions when the temperature drops below the dew point. In this study, we have investigated dew conditions on the skin of the gecko Lucasium steindachneri. When condensation occurs, we show that small dew drops, as opposed to a thin film, form on the lizard's scales. As the droplets grow in size and merge, they can undergo self-propulsion off the skin and in the process can be carried away a sufficient distance to freely engage with external forces. We show that factors such as gravity, wind and fog provide mechanisms to remove these small droplets off the gecko skin surface. The formation of small droplets and subsequent removal from the skin may aid in reducing microbial contact (e.g. bacteria, fungi) and limit conducive growth conditions under humid environments. As well as providing an inhospitable microclimate for microorganisms, the formation and removal of small droplets may also potentially aid in other areas such as reduction and cleaning of some surface contaminants consisting of single or multiple aggregates of particles.
authors.affiliation: School of Science and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia gwatson1@usc.edu.au.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Watson
authors.affiliation: School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Lin
authors.initials: L
authors.lastname: Schwarzkopf
authors.affiliation: Centre for Microscopy and Microanalysis and School of Biological Sciences, The University of Queensland, St Lucia, Queensland 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: Previously Queensland Department of Environment and Heritage Protection, GPO Box 2454, Brisbane, Queensland 4001, Australia.
authors.forename: Marty
authors.initials: M
authors.lastname: Gellender
authors.affiliation: School of Science and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia jolanta.watson@griffith.edu.au.
authors.forename: Jolanta A
authors.initials: JA
authors.lastname: Watson
mesh_terms: D000818:Animals; D006112:Gravitation; D008116:Lizards / Q000033:anatomy & histology / Q000502:physiology*; D008855:Microscopy, Electron, Scanning; D011793:Queensland; D012867:Skin / Q000648:ultrastructure*; D012879:Skin Physiological Phenomena; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D014919:Wind
chemical_list: D014867:Water
keywords: condensation; contaminants; dew; gecko; lizard; nanostructures