Bioinspired Ribbed Nanoneedles with Robust Superhydrophobicity

Authors

  • Xi Yao,

    1. Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China)
    2. Graduate School of Chinese Academy of Sciences Beijing 100080 (PR China)
    Search for more papers by this author
  • Qinwen Chen,

    1. Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China)
    2. Graduate School of Chinese Academy of Sciences Beijing 100080 (PR China)
    Search for more papers by this author
  • Liang Xu,

    1. Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China)
    2. Graduate School of Chinese Academy of Sciences Beijing 100080 (PR China)
    Search for more papers by this author
  • Qikai Li,

    1. Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China)
    Search for more papers by this author
  • Yanlin Song,

    1. Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China)
    Search for more papers by this author
  • Xuefeng Gao,

    Corresponding author
    1. Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215125 (PR China)
    • Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215125 (PR China).
    Search for more papers by this author
  • David Quéré,

    Corresponding author
    1. Physique et Mécanique des Milieux Hétérogènes UMR 7636 du CNRS, ESPCI 75005 Paris (France)
    • Physique et Mécanique des Milieux Hétérogènes UMR 7636 du CNRS, ESPCI 75005 Paris (France).
    Search for more papers by this author
  • Lei Jiang

    Corresponding author
    1. Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China)
    • Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 (PR China).
    Search for more papers by this author

Abstract

The robustness of superhydrophobicity is a fundamental issue for the applications of water-repellent materials. Inspired by the hierarchical structures of water-strider legs, this work describes a new water-repellent material decorated with ribbed, conical nanoneedles, successfully achieved on the surface of copper and consisting of copper hydroxide nanoneedle arrays sculptured with nanogrooves. The behavior of water drops on an as-prepared surface under various external disturbances is investigated. It is shown in particular that squeezing and relaxing drops between two such surfaces leads to a fully reversible exploration of the solid surface by the liquid, which is distinct from other superhydrophobic surfaces. This unique character is attributed to the penetrating Cassie state that occurs at the ribbed, conical nanoneedles. The proprietary lateral nanogrooves can, not only vigorously support the enwrapped liquid-air interface when a force is applied to the drop, but also provide reliable contact lines for the easy de-pinning of the deformed interface when the force is released from the drop. The results confirm the exceptional ability of strider legs to repel water, and should help to further the design of robust water-repellent materials and miniaturized aquatic devices.

Ancillary