Seamless Interfacial Connections for Long-Term Skin Monitoring

Seamless interfacial connections between the skin-sensors and sensor-electrodes in wearable electronics are crucial for reducing noise and ensuring reliable, long-term biosignal monitoring. However, most current systems rely on conductive gels with strong adhesives to achieve adherence to the skin, often leading to discomfort and degradation in performance over time. In addition, dry contact electrodes such as thin metal, conductive polymer, and composites rely on direct skin contact which can cause air gaps and loss of contact, severely compromising the quality of electrophysiological signals. Herein, we present a novel system with seamless interfacial connections, delivering high-fidelity, continuous skin monitoring. The nanoscale sensors demonstrate excellent skin conformability and low skin interfacial impedance, ensuring effective signal acquisition. Specifically, the integration of liquid metal with medical tape significantly improves the mechanical compliance of the sensor, resulting in an exceptionally high signal-to-noise ratio and minimal baseline noise oscillation when touching the interface with the sensor-electrodes. To validate the system, we measured both electrocardiogram and electromyogram signals during maximal voluntary contraction of the tibialis anterior, synchronizing the data with treadmill walking behavior over a two-day period. Compared to conventional gel electrodes, our system demonstrated superior signal amplitude, reduced baseline noise, and long-term stability, positioning it as an ideal solution for real-time healthcare, wearable diagnostics, and human-machine interfaces.