| Autor: |
Goh R; Materials Department, University of California, Santa Barbara, California 93106, United States., Danielsen SPO; Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States., Schaible E; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States., McMeeking RM; Mechanical Engineering Department, University of California, Santa Barbara, California 93106, United States., Waite JH; Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, United States. |
| Abstrakt: |
Structural versatility and multifunctionality of biological materials have resulted in countless bioinspired strategies seeking to emulate the properties of nature. The nanostructured egg case of swell sharks is one of the toughest permeable membranes known and, thus, presents itself as a model system for materials where the conflicting properties, strength and porosity, are desirable. The egg case possesses an intricately ordered structure that is designed to protect delicate embryos from the external environment while enabling respiratory and metabolic exchange, achieving a tactical balance between conflicting properties. Herein, structural analyses revealed an enabling nanolattice architecture that constitutes a Bouligand-like nanoribbon hierarchical assembly. Three distinct hierarchical architectural adaptations enhance egg case survival: Bouligand-like organization for in-plane isotropic reinforcement, noncylindrical nanoribbons maximizing interfacial stress distribution, and highly ordered nanolattices enabling permeability and lattice-governed toughening mechanisms. These discoveries provide fundamental insights for the improvement of multifunctional membranes, fiber-reinforced soft composites, and mechanical metamaterials. |
