Room-Temperature Processable Stretchable Conductive Composite Material for Electrical Interfacing in Stretchable Printed Circuit Boards

This study introduces a novel Room-Temperature Processable Stretchable Conductive Composite (RTPSC), uniquely combining room-temperature processability, stretchability, and conductivity. Unlike traditional conductive materials requiring thermal or UV curing, which can damage heat-sensitive components or cause substrate distortion, RTPSC uses a Styrene-Butadiene-Styrene (SBS) elastomer blended with silver conductive fillers and paraffin oil. This composition enables rapid solidification within five minutes at room temperature, mitigating thermal risks. Surface ligands on silver flakes are replaced with oleylamine, resulting in uniform silver distribution and enhanced resistance to acids, bases, and oxidation. The composite exhibits low contact resistance (0.1 Ω across 7.7 mm²) and maintains robust mechanical and electrical properties under extensive deformation, thanks to its high adhesion force (704.5 gF/25 mm). Notably, contact resistance change remains within 0.15 Ω even after 1800 cycles at 50% strain. RTPSC's viscosity can be finely tuned by adding solvents and secondary fluids, enabling various printing techniques from spray to omni-directional printing. This adaptability allows intricate patterning on delicate structures via spray printing and versatile connections between stretchable electrodes and rigid components through omni-directional printing. These capabilities provide extensive design flexibility and ease of repair, making RTPSC highly suitable for innovative development and maintenance of stretchable electronic devices.