Contact
    Start Publications Single-step fabrication of superhydrophobic surfaces by ...
    ←  Publication Finder
    Attension

    Single-step fabrication of superhydrophobic surfaces by two-photon polymerization micro 3D printing

    Year: 2023

    Journal: Micro and Nano Engineering, Volume 19, 2023-06-01, page 100192

    Authors: Bunea, Ada-Ioana; Szczotka, Nina; Navne, Jesper; Taboryski, Rafael

    Keywords: 3D printing; Superhydrophobic; Cassie-Baxter state; Wenzel state; Reentrant structures; Two-photon polymerization

    In this work, we fabricate a hexagonal array of pillars where each pillar has a “micro-hoodoo” shape, i.e., a reentrant cross section. The shape of the pillars makes them more resilient towards total wetting, i.e., transition from a Cassie-Baxter non-wetting state to a Wenzel wetting state. We show the single-step fabrication of 4 × 4 mm2 arrays by two-photon polymerization direct laser writing of the polydimethylsiloxane (PDMS)-derived commercial resin IP-PDMS. The use of a hydrophobic resin for rapid prototyping of reentrant structures enables the fabrication of surfaces patterns displaying superhydrophobic behavior despite the use of relatively simple structures, i.e. with a single reentrant surface. By changing the size of the micro-hoodoos and the packing density of the arrays, we map wetting behaviors ranging from the pinning of water droplets in Wenzel state to non-wetting Cassie-Baxter states. The measured contact angles follow quite well the theoretical results obtained by minimizing Gibbs free energy using the Wenzel, Cassie-Baxter and partial wetting theories. Among the tested micropatterns, five exhibited superhydrophobic properties, with a static contact angle with water as high as 158.1° ± 7.1°. This is the first demonstration of superhydrophobic surfaces produced by two-photon polymerization direct laser writing of PDMS in a single-step process.
    View publication