Stretchable Superhydrophobicity from Monolithic, Three-Dimensional Hierarchical Wrinkles

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Superhydrophobic surfaces offer excellent water repellency.
• Maintaining superhydrophobicity under mechanical stress, such as stretching, remains a challenge.
• Existing superhydrophobic materials often lose their properties when deformed.

Purpose of the Study:

• To design and fabricate three-dimensional (3D) hierarchical wrinkle substrates.
• To investigate the stretchability and durability of superhydrophobic properties.
• To understand the mechanisms behind maintained superhydrophobicity under strain.

Main Methods:

• Fabrication of monolithic poly(dimethylsiloxane) substrates with multiscale hierarchical wrinkles.
• Characterization of static and dynamic wetting properties (water contact angle, contact angle hysteresis, droplet impact behavior).
• Mechanical testing involving cyclic stretching up to 100% and 1000 cycles.

Main Results:

• The substrates exhibited static superhydrophobicity with water contact angles >160° and hysteresis <5°.
• Superhydrophobic bouncing behavior was observed upon droplet impact on the wrinkled surfaces.
• The surfaces maintained superhydrophobicity up to 100% stretching without structural defects after 1000 cycles.

Conclusions:

• The monolithic design and partial preservation of nanoscale structures enable stretchable superhydrophobicity.
• Hierarchical wrinkle substrates offer a promising platform for durable, water-repellent, and stretchable materials.
• These findings have implications for applications requiring robust superhydrophobic performance under mechanical deformation.