Reversible Adhesion via Light-Regulated Conformations of Rubber Chains

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Bio-inspired reversible adhesives are crucial for electronics, biomedicine, and robotics.
• Existing adhesives often rely on macroscopic deformation, limiting applications.
• Controlling adhesion at the nanoscale is an ongoing challenge.

Purpose of the Study:

• To demonstrate a new concept for in situ reversible adhesion by modulating polydimethylsiloxane (PDMS) chain conformations.
• To develop a light-controllable adhesive with enhanced adhesion properties.
• To avoid macroscopic deformation during adhesion switching.

Main Methods:

• Fabrication of a graphene/PDMS composite (GP) backing layer with a PDMS micropillar array.
• Utilizing the photothermal effect of graphene under UV irradiation to induce heating.
• Analyzing the change in PDMS chain conformations and contact points upon UV exposure.

Main Results:

• UV irradiation increased PDMS chain conformations and contact points, significantly enhancing adhesion.
• Adhesion switching was achieved without altering the macroscopic contact area.
• The photothermal effect of graphene enabled light-controllable adhesion switching.

Conclusions:

• A novel design principle for light-controllable structured adhesives was demonstrated.
• Modulating polymer chain conformations offers a new route for reversible adhesion.
• The developed adhesive concept is potentially applicable to other rubbery materials.