In Situ Synthesis of Biocompatible and Functionalizable Core–Shell Conductive Nanocomposites for Stretchable Electronics

Stretchable electronics are poised to revolutionize smart wearables and biomedical implants, yet their progress is hindered by the lack of biocompatible and easily functionalized conductors. While silver nanowire (Ag NW)-based composites show promise, their cytotoxicity and chemical instability often require complex passivation with noble metal coatings. Here, we introduce a scalable in situ synthesis that directly converts a patterned blend of Ag NWs and carbon nanotubes (CNTs) into a hierarchical core-shell architecture. The resulting material features a conductive nanocomposite core enveloped by a protective, CNT-rich shell, achieving high conductivity (5100 S/cm), stretchability (>200% strain), and carbon-like biocompatibility. Its broad electrochemical stability window permits direct electroplating of active materials required for physical and chemical sensing. We demonstrate the utility of this platform via soft electronic patches that conform to dynamic skins and organs. In a compelling in vivo application, these patches successfully recorded pathological electrograms and terminated arrhythmia via closed-loop pacing therapy on a rabbit heart. This work establishes a general strategy for creating biocompatible compliant conductors as a key enabler for stretchable devices in health monitoring, medical therapies, and human-machine interfaces.