3D-Printed Mixed Ionic–Electronic Conductive Polymer Composites for Long-Term Bioelectronic Sensing

This study reports the development of 3D-printable polymer composites designed for long-term bioelectronic sensing, specifically flexible ECG electrodes. The team engineered a mixed ionic–electronic conductor (OMIEC) combined with a siloxane crosslinked network, yielding a conductivity of 1.7 S cm⁻¹, high stretchability (253% strain at break), and stable electrical performance over 60 days. Through direct ink writing (DIW), the materials were fabricated into conformable ECG patches capable of recording heart signals continuously for 40 days without degradation. The results highlight a scalable manufacturing route for durable, biocompatible wearable electrodes.