Printable and Highly Stretchable Viscoelastic Conductors with Kinematically Reconstructed Conductive Pathways

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Printable and stretchable conductors are crucial for wearable electronics, soft robotics, and bio-integrated devices.
• Maintaining high electrical conductivity under large strain is a significant challenge.
• Controlling conductive filler microstructure during deformation is key to stable conductive pathways.

Purpose of the Study:

• To investigate the self-reorganization of silver (Ag) flakes within a polymer matrix under mechanical stretching.
• To develop high-performance, stable, printable, and stretchable conductive materials.
• To understand the mechanisms behind stretch-induced microstructural changes and conductivity enhancement.

Main Methods:

• Fabrication of metallic-filler-reinforced polymer composites using Ag flakes.
• Cyclic mechanical stretching of the composite materials.
• Electrical conductivity measurements at various strain levels.
• Dissipative particle dynamics (DPD) simulations to model filler behavior.

Main Results:

• Ag flakes spontaneously reorganize within the viscoelastic polymer matrix during cyclic stretching.
• Reconstructed microstructures form highly efficient and stable conductive pathways.
• Electrical conductivity is enhanced by 4-8 orders of magnitude, reaching approximately 10^4 S cm^-1.
• The phenomenon enables fabrication of high-performance stretchable conductors with reduced filler content.

Conclusions:

• The study demonstrates a novel self-reorganization mechanism for Ag flakes in polymer composites under stretching.
• This approach leads to significant improvements in electrical conductivity and stability for stretchable conductors.
• The developed materials show great promise for applications in soft and stretchable electronics, including wearable devices and LED arrays.