title: Superhydrophobic surfaces fabricated by femtosecond laser with tunable water adhesion: from lotus leaf to rose petal.
abstract: Superhydrophobic surfaces with tunable water adhesion have attracted much interest in fundamental research and practical applications. In this paper, we used a simple method to fabricate superhydrophobic surfaces with tunable water adhesion. Periodic microstructures with different topographies were fabricated on copper surface via femtosecond (fs) laser irradiation. The topography of these microstructures can be controlled by simply changing the scanning speed of the laser beam. After surface chemical modification, these as-prepared surfaces showed superhydrophobicity combined with different adhesion to water. Surfaces with deep microstructures showed self-cleaning properties with extremely low water adhesion, and the water adhesion increased when the surface microstructures became flat. The changes in surface water adhesion are attributed to the transition from Cassie state to Wenzel state. We also demonstrated that these superhydrophobic surfaces with different adhesion can be used for transferring small water droplets without any loss. We demonstrate that our approach provides a novel but simple way to tune the surface adhesion of superhydrophobic metallic surfaces for good potential applications in related areas.
authors.affiliation: †Laser Materials Processing Research Centre, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Jiangyou
authors.initials: J
authors.lastname: Long
authors.affiliation: †Laser Materials Processing Research Centre, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Peixun
authors.initials: P
authors.lastname: Fan
authors.affiliation: †Laser Materials Processing Research Centre, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Dingwei
authors.initials: D
authors.lastname: Gong
authors.affiliation: †Laser Materials Processing Research Centre, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Dafa
authors.initials: D
authors.lastname: Jiang
authors.affiliation: †Laser Materials Processing Research Centre, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: ‡Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, England.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: †Laser Materials Processing Research Centre, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Minlin
authors.initials: M
authors.lastname: Zhong
mesh_terms: D000268:Adhesiveness; D035264:Flowers / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007834:Lasers; D000070116:Lotus / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D027826:Rosa / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water
keywords: copper; femtosecond laser; microdroplet manipulation; superhydrophobic surface; tunable water adhesion