Mineral crystals enhance rasping power: chitons
The radular ribbons with which chitons scrape algae from rocks have enhanced rasping power because they contain layers of magnetite crystals within a chitin matrix.
| Biomimicry Taxonomy | |
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Break down > |
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Physically break down > |
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Biotic materials |
| Biomimetic Application Ideas | |
| Composite tools or machines for cutting (including on the nano- or micro-scales), more durable agricultural tools and implements. |
"The major lateral teeth of the chiton Acanthopleura echinata are composite structures composed of three distinct mineral zones: a posterior layer of magnetite; a thin band of lepidocrocite just anterior to this; and apatite throughout the core and anterior regions of the cusp. Biomineralization in these teeth is a matrix-mediated process, in which the minerals are deposited around fibers, with the different biominerals described as occupying architecturally discrete compartments. In this study, a range of scanning electron microscopes was utilized to undertake a detailed in situ investigation of the fine structure of the major lateral teeth. The arrangement of the organic and biomineral components of the tooth is similar throughout the three zones, having no discrete borders between them, and with crystallites of each mineral phase extending into the adjacent mineral zone. Along the posterior surface of the tooth, the organic fibers are arranged in a series of fine parallel lines, but just within the periphery their appearance takes on a
fish scale
-like
pattern, reflective of the cross section of a series of units that are
overlaid, and offset from each other, in adjacent rows. The units are
approximately 2 
m wide and 0.6 m thick and comprise biomineral plates separated by organic fibers. Two types of subunits make up each 'fish scale':
one is elongate and curved and forms a trough, in which the other,
rod-like unit, is nestled. Adjacent rod and trough units are aligned
into large sheets that define the fracture plane of the tooth. The
alignment of the plates of rod-trough units is complex and exhibits
extreme spatial variation within the tooth cusp. Close to the posterior
surface the plates are essentially horizontal and lie in a lateromedial
plane, while anteriorly they are almost vertical and lie in the
posteroanterior plane. An understanding of the fine structure of the
mineralized teeth of chitons, and of the relationship between the
organic and mineral components, provides a new insight into
biomineralization mechanisms and controls." (Wealthall et al. 2005:165) Acanthopleura
Organism/taxonomy data provided by:
Species 2000 & ITIS Catalogue of Life: 2008 Annual Checklist
Application Ideas: Composite tools or machines for cutting (including on the nano- or micro-scales), more durable agricultural tools and implements.
Industrial Sector(s) interested in this strategy: Nanotechnology, manufacturing, agriculture
Steven Vogel. 2003.
Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.
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Wealthall, Rosamund J; Brooker, Lesley R; Macey, David J; Griffin, Brendan J. Fine structure of the mineralized teeth of the chiton Acanthopleura echinata (Mollusca: Polyplacophora). Journal of Morphology. 265(2): 165-175.
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