Highly Elastic Hydrated Cellulosic Materials with Durable Compressibility and Tunable Conductivity.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Nanotechnology

Background:

• Anisotropic cellular materials offer unique properties for advanced applications.
• Fabrication challenges and performance limitations hinder the widespread use of such materials.
• Natural structures like tendons provide inspiration for designing advanced materials.

Purpose of the Study:

• To develop a facile, scalable method for fabricating highly elastic and ionically conductive anisotropic cellulosic materials.
• To mimic the hierarchical structure of tendons for enhanced material properties.
• To explore the potential applications of the fabricated material in various fields.

Main Methods:

• A top-down chemical treatment approach was used to modify natural wood.
• Lignin and hemicellulose were partially removed to soften cell walls.
• An interconnected cellulose fibril network was introduced within the wood structure.
• Atomistic and continuum modeling were employed to understand material behavior.

Main Results:

• The fabricated material, termed "elastic wood," demonstrated excellent elasticity and durable compressibility, with no fatigue after 10,000 cycles.
• The material exhibited high ionic conductivity (up to 0.5 mS cm⁻¹), tunable by compression ratio.
• Internal water movement was identified as key to accommodating large deformations and enabling shape recovery.
• The material combines an anisotropic cellular structure with a self-formed internal gel.

Conclusions:

• The developed method provides a scalable route to produce advanced anisotropic cellulosic materials from natural wood.
• Elastic wood possesses a unique combination of mechanical robustness, elasticity, and ionic conductivity.
• The material shows significant potential for applications in ionic nanofluidics, sensors, soft robotics, and energy storage.