Self-Adhesive Liquid Metal Channel Patch with Tip-Guided Conformal Coupling and Leakage Suppression for Skin...

Area of Science:

• Bioelectronics
• Materials Science
• Biomedical Engineering

Background:

• Conventional skin electrodes face challenges like dehydration, poor adhesion, and irritation, limiting long-term wearable bioelectronic applications.
• Existing electrodes often fail during motion, compromising biosignal monitoring accuracy and device longevity.

Purpose of the Study:

• To develop a novel skin-interfacing electrode patch with enhanced adhesion, signal quality, and durability for wearable bioelectronics.
• To address the limitations of current gel- and dry-type electrodes, particularly concerning motion artifacts and long-term wearability.

Main Methods:

• Development of a self-attachable liquid metal channel (S-LMC) patch integrating Galinstan microchannels and micropillar arrays with re-entrant geometries.
• Incorporation of a via-hole interconnect for direct vertical signal transmission, enabling compact system integration.
• Evaluation of skin adhesion, contact impedance, signal fidelity (ECG), and leakage resistance under various conditions.

Main Results:

• The S-LMC patch demonstrated strong, reusable skin adhesion (>60 kPa) and minimal skin irritation.
• Achieved low contact impedance (7.35 kΩ·cm² at 10 Hz) and significantly higher ECG signal fidelity (>2×) compared to commercial Ag/AgCl electrodes, especially under motion.
• Exhibited >2.4× higher long-term adhesion after 7 days and >2× higher critical pressure for leakage, indicating improved liquid metal confinement.

Conclusions:

• The S-LMC patch offers a promising solution for motion-resilient biosignal monitoring in wearable bioelectronics.
• Its unique re-entrant microarchitecture and integrated design overcome limitations of conventional electrodes, enabling scalable system integration.
• This technology paves the way for next-generation, skin-conformal bioelectronic interfaces with enhanced performance and user comfort.