Stress-Induced Shape-Shifting Materials Possessing Autonomous Self-Healing and Scratch-Resistant Ability

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Covalent adaptable networks (CANs) offer shape-shifting and self-healing properties, presenting an alternative to 4D printing for creating complex structures.
• Existing CANs often require specific stimuli like heat, light, or chemicals for shape manipulation, limiting their practical application in uncontrolled environments.

Purpose of the Study:

• To develop novel CANs that exhibit shape-shifting and self-healing capabilities under ambient conditions, triggered by external stress.
• To explore the potential of these stress-responsive CANs as a simplified approach to complex shape fabrication.

Main Methods:

• Synthesis of CANs utilizing a room-temperature exchangeable thia-Michael adduct.
• Characterization of material properties, including tensile strength and modulus.
• Evaluation of shape-shifting, stress-induced recyclability, self-welding, and self-healing behaviors under ambient conditions.

Main Results:

• The developed CANs demonstrate shape-shifting ability upon application of external stress, adapting to programmed forms.
• Materials exhibit significant tensile strength (up to 6 MPa) and modulus (up to 71.4 MPa).
• The CANs show stress-induced recyclability, self-welding, and self-healing properties at room temperature.

Conclusions:

• The novel CANs provide a versatile platform for stress-induced shape morphing and autonomous repair under ambient conditions.
• Their transparency and self-healing capabilities make them suitable for applications such as scratch-resistant coatings for display devices.