Leaf beetles inspire a new waterproof surface with concave

By mimicking the structure of a leaf beetle, the researchers developed a superhydrophobic surface that is resistant to the effects of water droplets and pressure. This technology is expected to enhance efficiency and reduce maintenance costs in various industries, including marine, aviation and energy. The results are published in Advanced materials.

Led by Professor Dong-Woo Lee at UNIST’s School of Energy and Chemical Engineering, the research team was inspired by the structure of the concave column (CP), found in some species of leaf beetles and the soil-dwelling springtail (Colembola) species. Based on this natural structure, the team implemented CP surfaces that can maintain superhydrophobicity even under harsh environmental conditions.

By taking advantage of these native structures found in nature, the researchers succeeded in preventing droplets from wetting the surface and achieved superior water resistance. The newly developed structure demonstrated much greater resistance to shock and water pressure compared to conventional highly hydrophobic surfaces.

Superhydrophobicity is defined as the property that allows water to flow easily without penetrating the surface. This property has many applications in different fields, including self-cleaning, anti-icing, and anti-fouling.

Highly hydrophobic surfaces exhibit limitations, especially in scenarios where surfaces easily get wet when water droplets are subjected to shock or pressure. To address these challenges, a stable anti-wetting mechanism is essential to maintain superhydrophobicity even under extreme conditions.

The research team used the concave structures observed in leaf beetles and soil-dwelling springtails as the basis for their work. By using this concept, they created CP surfaces with concave cavities that exhibited superhydrophobicity, even when subjected to high-speed water droplet collisions and high hydrostatic pressures.

Experimental results indicated that the CP structure experienced approximately 1.6 times greater resistance to wetting upon impact compared to the normal column (NP) structure. Under conditions of high water pressure, approximately 87% of the NP structure became wet, while only 7% of the CP structure became wetted.

The concave cavities generate an air cushion when in contact with water droplets, and act like a spring to prevent water penetration. As a result, the CP surface maintained stable superhydrophobicity for more than 24 h.

“We have provided a new direction for the design of stable, highly hydrophobic surfaces. If this design is successfully implemented, it is expected to make significant contributions across various industrial applications,” Professor Li stated.