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Toucan and hornbill beaks: A comparative study

Paper ID Volume ID Publish Year Pages File Format Full-Text
2044 99 2010 13 PDF Available
Title
Toucan and hornbill beaks: A comparative study
Abstract

The structure and mechanical behavior of Toco Toucan (Ramphastos toco) and Wreathed Hornbill (Rhyticeros undulatus) beaks were compared. The beak of both species is a sandwich-structured composite, having an exterior, or rhamphotheca, consisting of multiple layers of keratin scales and a core composed of a fibrous network of bony closed-cell foam. The rhamphotheca is an arrangement of ∼50 μm diameter, overlapping, keratin tiles. The hornbill rhamphotheca exhibits a surface morphology on the ridged casque that is distinguishable from that observed on the bill proper. Intermediate filaments in the keratin matrix were observed by transmission electron microscopy. The Young’s modulus measurements of toucan rhamphotheca indicate isotropy in longitudinal and transverse directions, whereas those of hornbill rhamphotheca may suggest anisotropy. The compressive response of beak foam is governed by brittle crushing behavior. The crushing strength of hornbill foam is six times higher than that of toucan foam. Micro- and nanoindentation hardness values were measured for rhamphotheca and foam trabeculae of toucan and hornbill specimens. The sandwich design of beaks was analyzed using the Karam–Gibson and Dawson–Gibson models. The presence of a cellular core increases the bending resistance (Brazier moment) by a factor of 3–6 while decreasing the compressive strength by only 50%.

Keywords
Toucan beak; Hornbill beak; Sandwich structure; Brazier moment
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Publisher
Database: Elsevier - ScienceDirect
Journal: Acta Biomaterialia - Volume 6, Issue 2, February 2010, Pages 331–343
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us