Matrix-Independent Highly Conductive Composites for Electrodes and Interconnects in Stretchable Electronics

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Electrically conductive composites (ECCs) are crucial for stretchable electronics due to their printability and elasticity.
• Improving conductivity in ECCs while maintaining mechanical properties is challenging, especially with matrix-specific approaches.
• Existing methods often limit material choices for polymer matrices, hindering diverse applications.

Purpose of the Study:

• To develop a generic approach for preparing ECCs with near-metal conductivity and stable performance during stretching.
• To overcome the limitations of matrix-specific treatments for conductive fillers.
• To enable flexible matrix selection for tailored ECC properties.

Main Methods:

• A novel method involving surfactant iodization on commercial silver flakes.
• Photo-induced conversion of silver iodide nanoparticles to silver nanoparticles.
• Fabrication of ECCs using these treated silver flakes within various polymer matrices.

Main Results:

• Achieved ECC conductivity comparable to bulk metals.
• Demonstrated sustained conductivity during mechanical stretching.
• The silver flake treatment is independent of the polymer matrix, offering broad applicability.
• ECCs showed excellent adhesion when matched with the substrate polymer for interconnects.
• Low-modulus matrices enabled enhanced skin contact for on-skin electrodes.

Conclusions:

• The developed generic approach significantly enhances ECC conductivity and stretchability.
• This method provides unprecedented flexibility in selecting polymer matrices for specific applications.
• The treated silver flakes offer a pathway to advanced stretchable electronics, including interconnects and on-skin devices.