Mechano-Regulable and Healable Silk-Based Materials for Adaptive Applications

Area of Science:

• Materials Science
• Biomaterials Engineering
• Nanotechnology

Background:

• Mechanically adaptive materials are crucial for intelligent devices but often lack facile property regulation.
• Achieving a wide range of mechanical properties, from high strength to extreme toughness, remains a significant challenge.
• Existing materials struggle with controllable and reversible changes in mechanical characteristics.

Purpose of the Study:

• To develop a mechano-regulable biopolymeric composite inspired by skeletal muscle.
• To create a material with tunable mechanical properties using dynamic coordination bonds and water as a regulator.
• To demonstrate the potential of this material in applications like iontronic skin and smart actuators.

Main Methods:

• A biopolymeric silk fibroin (SF) composite was engineered.
• Dynamic metal-ligand coordination bonds were regulated using water molecules as competitive agents.
• Tannic acid-tungsten disulfide nanohybrids were incorporated to enhance interfacial hydrogen bonding.

Main Results:

• The composite demonstrated an 837-fold change in Young's modulus (from 5.77 GPa to 6.89 MPa) upon water vapor exposure.
• The material exhibited high mechanical strength (72.5 MPa) and excellent self-healing capabilities (nearly 100% efficiency).
• Proof-of-concept applications in ultraconformable iontronic skin and smart actuators were successfully demonstrated.

Conclusions:

• The developed silk fibroin composite offers facile mechano-regulation of mechanical properties.
• The material's tunable strength and toughness, combined with self-healing, present a promising platform for adaptive smart devices.
• This work provides a new direction for designing advanced self-adaptive materials for next-generation intelligent systems.