Soy protein derived double network (DN) ionic conductive organohydrogel toward flexible strain sensor

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials

Background:

• Ionic conductive hydrogels are promising for flexible strain sensors.
• Challenges include achieving high strength, stretchability, conductivity, and environmental tolerance.
• Existing materials often struggle with simultaneous optimization of these properties.

Purpose of the Study:

• To develop a novel biocompatible soy protein-based ionic conductive organohydrogel.
• To enhance mechanical properties, ionic conductivity, and environmental stability.
• To demonstrate its application in wearable strain sensors.

Main Methods:

• Fabrication of a methacrylated soy protein isolate and poly(vinyl alcohol) (MSPI/PVA) double network (DN) structure.
• Reinforcement with tannic acid-coated cellulose nanocrystals (TCNC).
• Infiltration with a saturated NaCl solution in a glycerol/water binary solvent system.

Main Results:

• Achieved high gel strength (1.07 MPa) and strain (1321%).
• Exhibited high room temperature conductivity (3.23 S/m) and excellent low-temperature performance (flexible at -70 °C, 0.63 S/m at -40 °C).
• Demonstrated anti-drying properties (82% mass retention after 15 days) and stable sensing performance.

Conclusions:

• The developed organohydrogel successfully integrates high strength, stretchability, ionic conductivity, and environmental tolerance.
• It shows potential as a robust and reliable material for advanced flexible strain sensors.
• The material is suitable for fabricating wearable sensors for monitoring human body movements.