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Lessons from the Ocean: Whale Baleen Fracture Resistance
Author(s) -
Wang Bin,
Sullivan Tarah N.,
Pissarenko Andrei,
Zaheri Alireza,
Espinosa Horacio D.,
Meyers Marc A.
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201804574
Subject(s) - baleen , materials science , fracture toughness , composite material , anisotropy , whale , toughness , fracture (geology) , delamination (geology) , geology , biology , paleontology , physics , tectonics , quantum mechanics , subduction , fishery
Whale baleen is a keratin‐based biological material; it provides life‐long (40–100 years) filter‐feeding for baleen whales in place of teeth. This study reveals new aspects of the contribution of the baleen's hierarchical structure to its fracture toughness and connects it to the unique performance requirements, which require anisotropy of fracture resistance. Baleen plates are subjected to competing external effects of hydration and varying loading rates and demonstrate a high fracture toughness in transverse loading, which is the most important direction in the filtering function; in the longitudinal direction, the toughness is much lower since delamination and controlled flexure are expected and desirable. The compressive strength is also established and results support the fracture toughness measurements: it is also highly anisotropic, and exhibits a ductile‐to‐brittle transition with increasing strain rate in the dry condition, which is absent in the hydrated condition, conferring impact resistance to the baleen. Using 3D‐printing prototypes that replicate the three principal structural features of the baleen plate (hollow medulla, mineralized tubules, and sandwich‐tubular structure) are created, and the role of its structure in determining its mechanical behavior is demonstrated. These findings suggest new bioinspired engineering materials.