Robust Skin-Conformal Nano-Electrodes for Sustainable Health and Performance Monitoring
Jinyoung Kim, Sehyun Park, Jisoo Jeon, Donghee Kang, Gwendolyn M. Bryan, Timothy J. Broderick, Morley O. Stone, Vladimir V. Tsukruk
Abstract
Wearable electrodes with high conformability to the skin allow for a second-skin-like wearing experience and record high-quality electrophysiological signals over extended time in challenging environments. However, current research on skin-conformal electrodes faces limitations due to excessive motion artifacts under real-life external conditions. Here, we report a nanoscale skin-conformal electrode that enables continuous resilient electrophysiological signal monitoring with highly suppressed noise, low-motion artifacts, and high water-resilience, all unachievable with commercial gel electrodes. In particular, achieving a conformal skin-electrode interface provides mechanical and electrical stability under repeated dynamic stress (5000 times). The 300 nm nano-electrodes with dual hydrophilicity integrate a hydrophilic nanoscale 2D MXene conductor and a hydrophobic cross-linked parylene layer, ensuring highly conformal contact and long-term stable physical adherence to skin. This ultrathin design facilitates high physical adhesion and low skin interfacial impedance for continuous, reliable monitoring of electrocardiogram (ECG), and electromyogram (EMG) signals with a greatly increased signal-to-noise ratio. As a proof of concept, we successfully recorded high-quality ECG signals, allowing for the analysis of heart rate across diverse in-field testing. We further demonstrated concurrent EMG and ECG monitoring during treadmill walking, achieving stable, long-term signal acquisition, particularly in monitoring demanding human activity.