A Blueprint for Self‐Sharpening: Optimized Geometric Design Coupled With Multiscale Architecture in Northern Snakehead Teeth
Abstract
ABSTRACT The northern snakehead (Channa argus), an apex freshwater predator, possesses teeth that are a masterclass in biological design, achieving exceptional puncture resistance and autonomous self‐sharpening with minimalist material use. Here, through a multiscale investigation combining structural characterization, chemical mapping, and mechanical analysis, we decipher the key architectural principles underlying this evolutionary innovation. We reveal a thin enameloid cap with a functionally graded structure: a highly aligned, fluorapatite‐rich outer layer provides superior hardness (5.0 GPa), while a disordered inner layer enhances toughness through crack deflection. This efficient “hard‐soft” laminate is synergistically supported by a unique “mountain‐peak”‐shaped dentin‐enameloid junction (DEJ) that dissipates stress, and a dentin core reinforced with aligned collagen fibers and a hierarchical canal network for energy absorption. Crucially, we demonstrate that the tooth’s physiological curvature is not merely morphological but functional, guiding asymmetric wear on the concave side to continuously regenerate a sharp apex—a mechanism directly visualized via in situ compression 3D tomography. This work establishes the northern snakehead tooth as a model for efficient puncture, offering fundamental design blueprints for the next generation of biomimetic materials, particularly for lightweight, self‐sharpening, and puncture‐resistant devices.
Zhengyi Fu
Academician of the Chinese Academy of Engineering
Academician of the Chinese Academy of Engineering, Professor at Wuhan University of Technology.
Zhaoyong Zou
Professor
My research interests include bioprocess inspired fabrication, crystallization and ceramics.