Lignin-empowered self-healing biomass ionogels for multi-modal flexible sensing

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Conventional hydrogels and organogels for flexible electronics face challenges like dehydration, leakage, and limited multifunctionality.
• There is a growing demand for sustainable and green materials in flexible electronic applications.

Purpose of the Study:

• To develop a novel biomass-based ionogel with dual crosslinking networks for advanced flexible electronics.
• To investigate the mechanical properties, self-healing abilities, and multi-stimuli sensing capabilities of the developed ionogel.

Main Methods:

• Integration of lignin, poly(thioctic acid) (PTA), and a halometallate ionic liquid to create a covalent-physical dual crosslinking network.
• Characterization of mechanical properties (strength, elongation at break) and electrical conductivity.
• Evaluation of near-infrared (NIR)-accelerated self-healing and multi-stimuli sensing (strain, heat, NIR light).

Main Results:

• The optimized ionogel exhibits exceptional mechanical properties (75 kPa strength, 1230% elongation at break).
• The material demonstrates NIR-accelerated self-healing due to lignin's photothermal properties.
• The ionogel shows decent conductivity (0.026 S/m) and multi-stimuli sensing abilities via distinct electrical signal changes.

Conclusions:

• The developed ionogel offers a green and practical strategy for fabricating multifunctional flexible sensors.
• This work advances the high-value utilization of lignin in sustainable electronic materials.
• The ionogel serves as a versatile multi-modal flexible sensor for human motion monitoring and stimulus recognition.