Self-Adhesive Elastic Conductive Ink with High Permeability and Low Diffusivity for Direct Printing of Universal...

Area of Science:

• Materials Science
• Polymer Science
• Electronics Engineering

Background:

• Printed flexible electronics require robust conductive materials for deformable substrates.
• Challenges exist in creating stable electrical paths on porous, textured materials like textiles using conductive inks.

Purpose of the Study:

• To engineer a self-adhesive elastic conductive ink (ECI) for direct printing on various textiles.
• To achieve efficient electrode printing with continuous and stable electrical paths on diverse textile materials and structures.

Main Methods:

• Developed an ECI using a microphase separation-toughened elastomer (styrene-isoprene-styrene/ethyl vinyl acetate - SIS-EVA) and a binary conductive filler (silver flakes and liquid metal microspheres).
• Characterized the ECI's electromechanical properties, including breaking strain and conductivity.
• Evaluated the ECI's printability on diverse textiles, permeability, diffusivity, line width stability, and electrical stability under stretching and washing.

Main Results:

• The ECI demonstrated a high breaking strain of ~1305.5% and conductivity of ~5322.7 S cm⁻¹.
• Achieved efficient, pretreatment-free printing on various textiles with high permeability (319.2 μm) and low diffusivity (6.2 μm).
• Demonstrated stable printing line width (~216 μm) and maintained electrical stability after 200 stretching cycles (50% strain) and machine washability.

Conclusions:

• The engineered ECI offers a universal solution for printing stable, stretchable conductive electrodes on diverse textiles.
• The developed electronic textiles exhibit excellent stretchability, abrasion resistance, and machine washability, suitable for wearable applications.
• This advancement facilitates the integration of electronics into textiles for applications like fabric electrodes, sensors, and health monitoring.