Failure mechanisms in fibrous scaffolds

Area of Science:

• Biomaterials Science
• Materials Engineering
• Tissue Engineering

Background:

• Polymeric fibrous scaffolds mimic natural tissue microstructures for load-bearing applications.
• Poor toughness in fibrous materials leads to failure, a significant challenge in engineering and medicine.
• Understanding microscopic toughening mechanisms in fibrous scaffolds is limited due to visualization difficulties.

Purpose of the Study:

• To develop a novel method for visualizing detailed failure mechanisms in fibrous microstructures.
• To investigate the toughening mechanisms in different types of fibrous scaffolds.
• To provide insights for designing fibrous materials with improved toughness.

Main Methods:

• Development of a simple sample-taping technique for examining fibrous microstructure failure.
• Comparison of the sample-taping technique with in situ fracture testing using scanning electron microscopy.
• Analysis of failure modes in three distinct fibrous network types.

Main Results:

• Two distinct failure modes were identified in the examined fibrous scaffolds.
• Brittle cracking in gelatin electrospun scaffolds showed stable network morphology near the crack tip.
• Ductile failure in polycaprolactone electrospun scaffolds and nonwoven fabrics involved fiber rearrangement and the formation of toughening fiber bundles.

Conclusions:

• The formation of fiber bundles is a key mechanism for ductile failure and toughness enhancement.
• The sample-taping technique effectively visualizes microscopic failure mechanisms in fibrous materials.
• Insights gained can guide the development of tougher polymeric fibrous scaffolds for biomedical applications.