Heterogeneous Wettability-Based Construction of Two-Phase Interfaces for Underwater Reversible Adhesion

Area of Science:

• Materials Science
• Surface Chemistry
• Biomimetics

Background:

• Underwater smart adhesives are crucial for marine engineering and biomedical applications.
• Current challenges include achieving robust adhesion and on-demand detachment in aquatic environments.

Purpose of the Study:

• To design a novel underwater smart adhesive with switchable adhesion.
• To mimic the diving bell spider's strategy using heterogeneous wettability surfaces.

Main Methods:

• Fabrication of heterogeneous wettability surfaces with superhydrophobic (lipophilic) and hydrophilic regions.
• Confining an oil phase within air cavities to form annular oil rings and isolate a water bridge.
• Utilizing Laplace pressure at oil/water interfaces for adhesion.
• Employing electrolysis for on-demand detachment.

Main Results:

• Demonstrated robust adhesion through stable oil/water interfaces.
• Showcased linear enhancement of adhesion strength with multiple interfaces.
• Achieved rapid detachment via controlled electrolysis.
• Integrated the adhesive into an unmanned underwater vehicle (UUV) for practical applications.

Conclusions:

• The heterogeneous wettability surface design provides a viable strategy for switchable underwater adhesion.
• The developed adhesive shows significant potential for underwater anchoring and other marine engineering scenarios.