Flexible Strain Sensor Based on PVA/Tannic Acid/Lithium Chloride Ionically Conductive Hydrogel with Excellent Sensing...

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Ion-conductive hydrogels are crucial for flexible sensing and bioelectric monitoring due to their skin conformability and signal transmission.
• Traditional hydrogel preparation methods struggle with poor adhesion, conductivity, and mechanical stability.

Purpose of the Study:

• To develop an ion-conductive hydrogel with improved adhesion, conductivity, and mechanical stability.
• To explore the potential of this hydrogel in strain sensing and bioelectric signal monitoring applications.

Main Methods:

• Utilized a freeze-thaw cycling method for hydrogel preparation.
• Employed polyvinyl alcohol (PVA) as the matrix, tannic acid (TA) for adhesion reinforcement, and lithium chloride (LiCl) as the conductive medium.

Main Results:

• The optimized PVA-TA-0.5/LiCl-1 hydrogel achieved an adhesion strength of 2.32 kPa on pigskin and a conductivity of 0.64 S/m.
• Demonstrated excellent sensitivity (GF = 1.15) and operational stability, with minimal signal change after 2500 stretching cycles.
• Exhibited superior strain sensing and electromyographic signal acquisition capabilities.

Conclusions:

• The developed ion-conductive hydrogel offers superior comprehensive performance compared to traditional methods.
• This hydrogel shows significant potential for practical applications in flexible sensing and bioelectric monitoring.