Polysaccharide-driven self-healing dual-network hydrogel via Schiff base for high-performance flexible sensing

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Conductive hydrogels are promising for flexible wearable sensors due to flexibility, conductivity, and biocompatibility.
• Traditional hydrogels suffer from irreversible mechanical damage and performance decay due to static covalent cross-linked networks.

Purpose of the Study:

• To develop a dual-network ion-conductive self-healing hydrogel using natural polysaccharides.
• To overcome the limitations of traditional hydrogels in terms of mechanical damage and performance decay for enhanced wearable sensor applications.

Main Methods:

• Synthesized a dual-network hydrogel with polyacrylamide (PAM) forming a rigid covalent network and sodium alginate oxide (OSA) forming a flexible network cross-linked via Schiff base bonds.
• Incorporated carboxylate groups from OSA and a phosphate buffer system for ionic conduction and adhesion.
• Investigated self-healing properties, extensibility, ionic conductivity, and strain sensitivity.

Main Results:

• Achieved rapid self-healing (95.69% recovery in 25 min) and high extensibility (~770%) at room temperature.
• Demonstrated efficient ionic conduction and strong adhesion.
• Exhibited stability under large deformation and high strain sensitivity (GF = 2.945) for precise human motion monitoring.

Conclusions:

• The developed hydrogel offers a synergistic 'rigid support-dynamic healing-ionic conductivity' mechanism.
• This innovative strategy enables the design of safe, reliable, long-lasting, and fatigue-resistant wearable sensors.
• The hydrogel's properties are ideal for precise real-time monitoring of complex human motions.