Damage-resistant and body-temperature shape memory skin-mimic elastomer for biomedical applications.

Area of Science:

• Material Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Integrating high strength, toughness, damage resistance, body-temperature shape memory, and biosafety into a single skin-mimic material is a significant challenge.
• Existing materials often lack a comprehensive combination of these critical properties for advanced applications.

Purpose of the Study:

• To develop a novel polyurethane elastomer system that integrates multiple advanced properties for skin-mimic applications.
• To achieve high mechanical performance, body-temperature shape memory, and biosafety within a single material.

Main Methods:

• Utilized a "Lego-like" polyurethane (PU) design with multilevel structures.
• Engineered chemical and sequence structures of blocks, coordinated hydrogen bonds, and controlled microphase separation and crystallization.
• Incorporated crystallization and physical cross-linking for enhanced properties.

Main Results:

• Obtained an elastomer with exceptional true tensile strength (1.42 GPa) and high fracture energy (384.7 ± 18.9 kJ/m²).
• Demonstrated skin-like nonlinear mechanoresponse and excellent body-temperature shape memory properties suitable for 4D printing.
• Confirmed the material's biosafety, with potential to promote cell proliferation and DNA repair.

Conclusions:

• The developed "Lego-like" PU elastomer successfully integrates high strength, toughness, damage resistance, shape memory, and biosafety.
• This multifunctional material shows significant promise for advanced biomedical applications, including minimally invasive surgery and tissue engineering.
• The material's properties make it suitable for innovative 4D printing applications in the biomedical field.