Adhesion performance of magnetically responsive surfaces under wet conditions

Area of Science:

• Materials Science
• Surface Science
• Robotics

Background:

• Reversible wet adhesion is crucial for manipulating objects in liquid environments.
• Existing micropillar and external stimuli methods lack detailed understanding of liquid/solid regulation mechanisms.
• Developing controllable wet adhesion surfaces is an ongoing challenge.

Purpose of the Study:

• To investigate the mechanisms of liquid/solid regulation in magnetically responsive micropillar arrays.
• To evaluate the effect of geometric structures (pointed vs. flat terminals) and magnetic fields on wet adhesion performance.
• To demonstrate the practical application potential of these surfaces.

Main Methods:

• Fabrication of magnetically responsive micropillar arrays with pointed and flat terminals using spray self-assembly.
• In situ observation and theoretical modeling to analyze adhesive forces and liquid bridge dynamics.
• Wet adhesion measurements under cyclic magnetic field application.

Main Results:

• Adhesive forces are primarily influenced by liquid bridge length and apparent contact angle.
• Micropillar arrays with flat terminals achieved the highest adhesion conversion efficiency (72%) under magnetic fields, over three times that of pointed terminals.
• The developed surfaces demonstrated high durability and cyclic reversibility.

Conclusions:

• Magnetically responsive micropillar arrays, particularly those with flat terminals, provide an effective solution for controllable wet adhesion.
• The findings offer insights into liquid/solid regulation mechanisms and have implications for transfer printing and wet robotics.
• This research paves the way for advanced microhandling and locomotion systems in wet conditions.