Interface-Encoded Dynamic Covalent Crosslinking Enables Ultra-Stretchable, Signal-Stable Conductive Elastomers

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Soft electronics require conductive materials with high elasticity and stretchability.
• Existing conductive elastomers face a trade-off between filler-matrix adhesion and mechanical properties.
• Interfacial defects and stress concentration limit performance under dynamic strain.

Purpose of the Study:

• To resolve the adhesion-elasticity trade-off in conductive elastomers.
• To engineer dynamic covalent interfaces for enhanced electromechanical stability.
• To develop ultra-stretchable, tough, and self-healing conductive materials.

Main Methods:

• Functionalizing carbon nanofibers (CNFs) with lipoic acid.
• Utilizing reversible disulfide exchange at the CNF-elastomer interface.
• Employing density functional theory (DFT) for mechanism analysis.
• Characterizing mechanical, electrical, and self-healing properties.

Main Results:

• Achieved ultra-stretchability (∼4200%) and enhanced toughness.
• Demonstrated 3-5x higher conductivity compared to controls.
• Enabled wide-range strain sensing (0%-3000%) with high gauge factors.
• Exhibited reproducible, low-hysteresis responses under large strains.
• Showcased room-temperature self-healing and recyclability.

Conclusions:

• Dynamic covalent interface engineering overcomes limitations in conductive elastomers.
• The developed materials offer superior stretchability, conductivity, and stability.
• This work presents a molecular design principle for advanced, sustainable soft electronic materials.