Micro-Texturized and Ultra-Soft Dry Electrode for Motion-Artifact Tolerant and Long-Term Stable Wearable...

Accurate and robust acquisition of electrophysiological signals is essential for wearable healthcare and human-machine interface applications. However, conventional wet electrodes are limited by motion artifacts and insufficient long-term stability, while many dry electrodes lack adequate skin adhesion and mechanical compliance. Here, we present a carbon black (CB)-polydimethylsiloxane (PDMS) composite-based dry electrode featuring a micro-textured surface (R_a ≈ 1 µm), low modulus (∼216 kPa), and strong adhesive strength (∼15.68 kPa), conformally integrated onto a stretchable metallic interconnector with an optimized serpentine geometry (235° curvature angle). This architecture achieves high performance without fabrication complexity by leveraging spontaneously formed micro-textures to promote mechanical interlocking for robust skin adhesion, thereby ensuring low interfacial impedance (∼165.2 kΩ·cm² at 100 Hz) and enabling long-term electrical and mechanical stability. To demonstrate real-world applicability, we developed a wireless, miniaturized electrocardiogram (ECG) system integrated with an inertial measurement unit (IMU). The system achieved significantly higher signal-to-noise ratios (SNR) than commercial devices across diverse activities (16.82-26.19 dB vs. 4.98-13.8 dB) and maintained an SNR of 21.07 dB after 24 h of continuous monitoring. These results highlight the potential of the proposed electrode system as a scalable and practical solution for high-fidelity, long-term biosignal acquisition in wearable electronics.