Environmentally Stable N‐Type Conducting Polymer with High Intrinsic Stretchability

ABSTRACT The development of flexible electronics has driven an urgent demand for conducting polymers that combine exceptional electrical performance with mechanical adaptability. In the construction of complementary circuits, integrating p‐type and n‐type conducting polymers is critical, yet developing stretchable n‐type ones has long remained a challenge. We employ the refined regulation of polymer‐polymer interaction to enhance PBFDO's intrinsic stretchability (crack‐onset strain up to 100%) and environmental stability (5‐fold stability enhancement vs. pristine PBFDO), while achieving 2265 S/cm conductivity at 100% strain with stable recovery after 1000 cycles. Building on these advancements, we have successfully developed stretchable epidermal electrophysiological electrodes and organic thermoelectric devices—each conclusively validating the material's practical utility. The epidermal electrodes enable high signal‐to‐noise ratio recording of electrophysiological signals, while the thermoelectric devices operate stably under 60% bidirectional tensile strain. This work thus establishes new fundamental principles for engineering high‐performance stretchable n‐type conducting polymers, paving the way for next‐generation flexible electronics.