An Ultrastretchable and Self-Healable Nanocomposite Conductor Enabled by Autonomously Percolative Electrical Pathways

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Previous self-healable and stretchable conductors faced limitations in achieving simultaneous high stretchability, conductivity, and self-healability.
• Simultaneously optimizing these properties in electronic materials remains a significant challenge.

Purpose of the Study:

• To develop an ultrastretchable and self-healable nanocomposite conductor with enhanced conductivity.
• To investigate the phenomenon of "electrical self-boosting" for reconstructing conductive pathways.
• To demonstrate the potential of this material in advanced applications like human-robot interfaces.

Main Methods:

• Fabrication of an ultrastretchable and self-healable nanocomposite conductor using silver flakes and a self-healing polymer matrix.
• Utilizing microcomputed tomography and in situ scanning electron microscopy to verify pathway reconstruction.
• Conducting tensile strain tests up to 3500% and cyclic stretching tests.
• Demonstrating electromyogram signal monitoring for prosthetic robot control.

Main Results:

• The nanocomposite conductor exhibited "electrical self-boosting", autonomously reconstructing conductive pathways under strain (over 1700%).
• Exceptional conductivity (average 2578 S cm^-1) was maintained at 3500% tensile strain.
• The material retained high conductivity and stretchability even after complete severance and demonstrated durable performance in cyclic tests.
• Successful monitoring of electromyogram signals for controlling prosthetic hand motions was achieved.

Conclusions:

• The developed ultrastretchable and self-healable conductor overcomes previous limitations by achieving simultaneous high stretchability, conductivity, and self-healability.
• The "electrical self-boosting" phenomenon is crucial for maintaining electrical integrity in highly deformed materials.
• This material holds significant promise for next-generation wearable electronics, soft robotics, and advanced human-robot interfaces.