TY - JOUR
T1 - Radular stylus of Cryptochiton stelleri : a multifunctional lightweight and flexible fiber-reinforced composite
AU - Pohl, Anna
AU - Herrera, Steven A.
AU - Restrepo, David
AU - Negishi, Ryo
AU - Jung, Jae-Young
AU - Salinas, Chris
AU - Wuhrer, Richard
AU - Yoshino, Tomoko
AU - McKittrick, Joanna
AU - Arakaki, Atsushi
AU - Nemoto, Michiko
AU - Zavattieri, Pablo
AU - Kisailus, David
PY - 2020
Y1 - 2020
N2 - Chitons are herbivorous invertebrates that use rows of ultrahard magnetite-based teeth connected to a flexible belt (radula) to rasp away algal deposits growing on and within rocky outcrops along coastlines around the world. Each tooth is attached to the radula by an organic structure (stylus) that provides mechanical support during feeding. However, the underlying structures within the stylus, and their subsequent function within the chiton have yet to be investigated. Here, we investigate the macrostructural architecture, the regional material and elemental distribution and subsequent nano-mechanical properties of the stylus from the Northern Pacific dwelling Cryptochiton stelleri. Using a combination of μ-CT imaging, optical and electron microscopy, as well as elemental analysis, we reveal that the stylus is a highly contoured tube, mainly composed of alpha-chitin fibers, with a complex density distribution. Nanoindentation reveals regiospecific and graded mechanical properties that can be correlated with both the elemental composition and material distribution. Finite element modeling shows that the unique macroscale architecture, material distribution and elemental gradients have been optimized to preserve the structural stability of this flexible, yet robust functionally-graded fiber-reinforced composite tube, providing effective function during rasping. Understanding these complex fiber-based structures offers promising blueprints for lightweight, multifunctional and integrated materials.
AB - Chitons are herbivorous invertebrates that use rows of ultrahard magnetite-based teeth connected to a flexible belt (radula) to rasp away algal deposits growing on and within rocky outcrops along coastlines around the world. Each tooth is attached to the radula by an organic structure (stylus) that provides mechanical support during feeding. However, the underlying structures within the stylus, and their subsequent function within the chiton have yet to be investigated. Here, we investigate the macrostructural architecture, the regional material and elemental distribution and subsequent nano-mechanical properties of the stylus from the Northern Pacific dwelling Cryptochiton stelleri. Using a combination of μ-CT imaging, optical and electron microscopy, as well as elemental analysis, we reveal that the stylus is a highly contoured tube, mainly composed of alpha-chitin fibers, with a complex density distribution. Nanoindentation reveals regiospecific and graded mechanical properties that can be correlated with both the elemental composition and material distribution. Finite element modeling shows that the unique macroscale architecture, material distribution and elemental gradients have been optimized to preserve the structural stability of this flexible, yet robust functionally-graded fiber-reinforced composite tube, providing effective function during rasping. Understanding these complex fiber-based structures offers promising blueprints for lightweight, multifunctional and integrated materials.
UR - https://hdl.handle.net/1959.7/uws:60012
U2 - 10.1016/j.jmbbm.2020.103991
DO - 10.1016/j.jmbbm.2020.103991
M3 - Article
SN - 1751-6161
VL - 111
JO - Journal of The Mechanical Behavior of Biomedical Materials
JF - Journal of The Mechanical Behavior of Biomedical Materials
M1 - 103991
ER -