Highly Corrosion-Resistant Ultrafine Silver Fiber Biopotential Sensor for Long-Term Monitoring

Area of Science:

• Materials Science and Engineering
• Biomedical Engineering
• Electrochemistry

Background:

• Fabric electrodes are crucial for wearable medical-health-monitoring garments.
• Sweat corrosion significantly degrades the longevity and stability of existing fabric electrodes.
• Need for robust and stable biopotential sensors for continuous physiological monitoring.

Purpose of the Study:

• To chemically modify metal fabric biopotential sensors with 3-mercaptopropyltrimethoxysilane (MPTS) to enhance corrosion resistance.
• To investigate the anticorrosion mechanism of MPTS using molecular dynamics (MD) simulations.
• To evaluate the electrochemical properties, durability, and suitability of modified electrodes for wearable applications.

Main Methods:

• Chemical modification of metal fabric electrodes with MPTS.
• Formation of Ag/AgCl on electrode surfaces via constant voltage deposition.
• Preparation of various electrode types: Ag/AgCl/MPTS/SPNE, Ag/AgCl/MPTS/SPCWE, and Ag/AgCl/MPTS/SSYE.
• Molecular dynamics (MD) simulations for anticorrosion mechanism analysis.
• Electrochemical property testing in simulated sweat and NaCl solutions.
• Durability tests including softness, abrasion, washing, and motion noise resistance.

Main Results:

• Ag/AgCl/MPTS/SSYE demonstrated optimal corrosion resistance in simulated sweat and NaCl solutions.
• The modified electrodes exhibited excellent softness, abrasion resistance, washing resistance, and motion noise resistance.
• MD simulations provided insights into the anticorrosion mechanism of MPTS.
• Optimized dip-coating time and chlorination parameters improved electrochemical properties.

Conclusions:

• The Ag/AgCl/MPTS/SSYE electrode offers superior corrosion resistance, comfort, and electrical properties for wearable applications.
• This enhanced biopotential sensor is suitable for long-term monitoring of electrocardiogram (ECG) and electromyogram (EMG) signals.
• The developed electrode technology supports applications in neuromuscular electrical stimulation (NMES) and continuous health tracking.