Biomimetic Superhydrophobic Engineering Metal Surface with Hierarchical Structure and Tunable Adhesion: Design of Microscale Pattern

Lotus leaves and rose petals are both typical natural superhydrophobic surfaces, with low and high adhesion, respectively. This fact inspires us to prepare superhydrophobic surfaces with different levels of adhesion on iron by mimicking their hierarchical structures through three simple steps: abrasion, calcination, and modification. A uniform and stable super hydrophobic iron surface with excellent adaptability and wearability can be obtained, and its adhesion is tunable. The results confirmed that superhydrophobicity and adhesion are both dependent on the synergy of the microscale and nanoscale patterns of the hierarchical structure generated by the designed abrasion and thermal treating. The adhesion level can be controlled by simply adjusting the abrasion program to obtain the desired microscale pattern with a proper ratio of height-to-width of the microstructure. This easy, inexpensive, and clean three-step method is widely applicable for different engineering metals and alloys and suitable for large-scale production.