The effect of hydrophobicity of micro/nanostructured-surfaces on behaviours of water spreading

Hailong Zhang, Reinhard Boysen, Genna Sune, Xavier Borrise, Francesc Perez-Murano, Milton Thomas William Hearn, Dan Nicolau

    Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

    Abstract

    Atomic force microscopy (AFM) in conjunction with cross-section analysis was applied to determine the distribution, position and contact angle of spray-deposited water micro-droplets on micro-structured arrays. For this investigation, two micro-structured arrays on silicon wafers with a chessboard pattern of depressions and protrusions of various sizes were manufactured by e-beam lithography. The first array had a silicon oxide/silicon structure (hydrophilic/hydrophilic) with an elevated silicon oxide layer of 40 nm and the second had a gold/silicon structure (hydrophobic/hydrophilic) with an elevated gold layer of 35 nm. On the first array with only hydrophilic surfaces, the behavior of the water droplets was mainly affected by topography, whereby the contact angles on the structures were considerably higher than the contact angles of droplets on unstructured reference surfaces. On the second array the water micro-droplets were confined in the hydrophilic depressions by the hydrophobic boundary whereby the highest contact angle was measured on the smallest squares and the lowest contact angle was found on the largest I?m exceeding the contact angles of the droplets on the unstructured reference materials.
    Original languageEnglish
    Title of host publicationBiomedical applications of micro- and nanoengineering IV and complex systems
    EditorsDan V Nicolau, Guy Metcalfe
    Place of PublicationUSA
    PublisherSPIE
    Pages727009-1 - 727009-8
    Number of pages8
    Volume7270
    ISBN (Print)9780819475220
    DOIs
    Publication statusPublished - 2008
    EventSPIE: Smart Materials, Nano+Micro-Smart Systems 2008 - Melbourne Australia, USA
    Duration: 1 Jan 2008 → …

    Conference

    ConferenceSPIE: Smart Materials, Nano+Micro-Smart Systems 2008
    CityUSA
    Period1/01/08 → …

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