Tattoo electronics, flexible patches that mount directly onto the skin with the ease and flexibility of a temporary tattoo, have foreseen remarkable application potentials in personalized healthcare monitoring and human-machine interfaces. Documented tattoo electronics mostly have an on-skin form factor to date. Using dermal tattoos for in vivo diagnostics presents an unexplored paradigm. Here, we extend the application scenario of “tattoo electrodes” from an on-skin fashion to an actual under-skin configuration, enabled by a highly soft, conductive, and biocompatible polymer matrix. With printed ultrathin electrodes, we achieve a record-high conductivity and record-low skin contact impedance, allowing the design of a single-lead electrocardiogram system for seamless wearing and precise detection of intervals and rhythms in dynamic conditions. Furthermore, the biocompatible ink enables the development of dermal electrodes by virtue of tattoo artistry. It shows enormous potential for electrical communication between bioelectronics and biological tissues at a deep-tissue level.

纹身电子产品是一种灵活的贴片，可以像临时纹身一样轻松灵活地直接贴在皮肤上，在个性化医疗监控和人机界面方面具有非凡的应用潜力。迄今为止，记录在案的纹身电子产品大多具有皮肤外形。在体内使用真皮纹身诊断学提出了一个未探索的范例。在这里，我们将“纹身电极”的应用场景从皮肤上的时尚扩展到实际的皮下配置，由高度柔软、导电和生物相容的聚合物基质实现。通过印刷超薄电极，我们实现了创纪录的高电导率和创纪录的低皮肤接触阻抗，从而允许设计单导联心电图系统，以实现无缝佩戴并精确检测动态条件下的间隔和节律。此外，生物相容性墨水可以通过纹身艺术开发真皮电极。它显示了在深层组织水平上生物电子学和生物组织之间进行电通信的巨大潜力。