Electrically Switchable Molecular Adhesion via Self-Assembled Monolayer-Mediated Hydration and Ion Structuring

Area of Science:

• Surface Science
• Colloid and Interface Science
• Nanotechnology

Background:

• Intermolecular and intersurface forces at solid-liquid interfaces are crucial for surface-mediated functions in biological and technological systems.
• Ion and hydration structuring at interfaces are influenced by surface properties like potential, adsorbents, and electrolyte composition.
• Understanding these interactions is key to controlling adhesion and repulsion.

Purpose of the Study:

• To disclose an electromechanical adhesion switch mechanism.
• To demonstrate the impact of molecular surface modification and potential modulation on adhesive and repulsive forces.
• To analyze the role of ion ordering in shaping solid-solid interactions.

Main Methods:

• Utilizing an electrochemical surface forces apparatus.
• Performing molecular dynamics simulations.
• Measuring intermolecular forces between mica and modified metal surfaces (mercaptobenzimidazole, cysteamine films).

Main Results:

• Demonstrated an operational electromechanical adhesion switch.
• Showcased the ability to tailor surface interactions via ion adsorption manipulation.
• Provided a comprehensive analysis of forces and ion ordering under electrochemical modulation.

Conclusions:

• Hydration and ion adsorption significantly influence solid-solid interactions involving organic thin films.
• These interactions offer a flexible route for developing electromechanical adhesion switches.
• The findings offer novel insights into controlling interfacial forces.