Nanolatticed Architecture Mitigates Damage in Shark Egg Cases

Area of Science:

• Bioinspired materials science
• Biomimetics and structural biology

Background:

• Biological materials often display remarkable structural versatility and multifunctionality.
• The swell shark egg case is a prime example, known for its toughness and permeability, balancing conflicting material properties.

Purpose of the Study:

• To investigate the nanostructure of the swell shark egg case.
• To understand how its architecture achieves both strength and porosity for embryo protection and exchange.

Main Methods:

• Detailed structural analyses of the swell shark egg case.
• Examination of its hierarchical nanolattice architecture and nanoribbon assembly.

Main Results:

• The egg case features a Bouligand-like nanoribbon hierarchical assembly.
• Three key adaptations identified: Bouligand-like organization for reinforcement, noncylindrical nanoribbons for stress distribution, and ordered nanolattices for permeability and toughening.

Conclusions:

• The swell shark egg case's nanostructure provides a model for creating advanced multifunctional membranes.
• Insights gained can advance the design of fiber-reinforced soft composites and mechanical metamaterials.