Structure and mechanical behavior of a toucan beak

Seki, Yasuaki; Schneider, M. S.; Meyers, Marc A.

doi:10.1016/j.actamat.2005.04.048

Cited by 114 publications

(100 citation statements)

References 25 publications

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“…Epidermis, dermis and bone are anchored to each other with collagenous Sharpey's fibres (bone -dermis interaction) or numerous tissue interdigitations (dermis -epidermis interaction; A.G., personal observation; in figure 1a). Previous work on the composite structure and the mechanical behaviour of a toucan beak was done by Seki and co-workers [7,8]. They found that the toucan beak consists of a trabecular bony core, a cortical shell and a keratin shell.…”

Section: Introductionmentioning

confidence: 99%

Multi-layered bird beaks: a finite-element approach towards the role of keratin in stress dissipation

Soons

Herrel

Genbrugge

et al. 2012

J. R. Soc. Interface.

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Bird beaks are layered structures, which contain a bony core and an outer keratin layer. The elastic moduli of this bone and keratin were obtained in a previous study. However, the mechanical role and interaction of both materials in stress dissipation during seed crushing remain unknown. In this paper, a multi-layered finite-element (FE) model of the Java finch's upper beak (Padda oryzivora) is established. Validation measurements are conducted using in vivo bite forces and by comparing the displacements with those obtained by digital speckle pattern interferometry. Next, the Young modulus of bone and keratin in this FE model was optimized in order to obtain the smallest peak von Mises stress in the upper beak. To do so, we created a surrogate model, which also allows us to study the impact of changing material properties of both tissues on the peak stresses. The theoretically best values for both moduli in the Java finch are retrieved and correspond well with previous experimentally obtained values, suggesting that material properties are tuned to the mechanical demands imposed during seed crushing.

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Section: Introductionmentioning

confidence: 99%

Multi-layered bird beaks: a finite-element approach towards the role of keratin in stress dissipation

Soons

Herrel

Genbrugge

et al. 2012

J. R. Soc. Interface.

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“…There is an apparent optimization of weight to strength through sandwich structures consisting of solid shells filled with compliant cellular cores [12,13]. The core significantly increases the buckling capabilities of the entire system while maintaining the light weight required for flight.…”

Section: Aerospace Materialsmentioning

confidence: 99%

“…This is by no means an exhaustive list, and there are many systems that have only been superficially investigated. We are currently investigating: abalone [8,9], conch [10,11], toucan beaks [12,13], and crab exoskeleton [14]. We add the silica spicules, that have been studied and extensively described by Mayer and coworkers [6,7], as well some other selected systems.…”

Section: Introduction and Basic Overview Of Mechanical Propertiesmentioning

confidence: 99%

Biological materials: Structure and mechanical properties

Meyers

Chen

Lin

et al. 2008

Progress in Materials Science

2,131

1,129

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Most natural (or biological) materials are complex composites whose mechanical properties are often outstanding, considering the weak constituents from which they are assembled. These complex structures, which have risen from hundreds of million years of evolution, are inspiring Materials Scientists in the design of novel materials.Their defining characteristics, hierarchy, multifunctionality, and self-healing capability, are illustrated. Self-organization is also a fundamental feature of many biological materials and the manner by which the structures are assembled from the molecular level up. The basic building blocks are described, starting with the 20 amino acids and proceeding to polypeptides, polysaccharides, and polypeptides-saccharides. These, on their turn, compose the basic proteins, which are the primary constituents of 'soft tissues' and are also present in most biominerals. There are over 1000 proteins, and we describe only the principal ones, with emphasis on collagen, chitin, keratin, and elastin. The 'hard' phases are primarily strengthened by minerals, which nucleate and grow in a biomediated environment that determines the size, shape and distribution of individual crystals. The most important mineral phases are discussed: hydroxyapatite, silica, and aragonite.Using the classification of Wegst and Ashby, the principal mechanical characteristics and structures of biological ceramics, polymer composites, elastomers, and cellular materials are presented. Selected systems in each class are described with emphasis on the relationship between their structure and mechanical response. A fifth class is added to this: functional biological materials, which have a structure developed for a specific function: adhesion, optical properties, etc.An outgrowth of this effort is the search for bioinspired materials and structures. Traditional approaches focus on design methodologies of biological materials using conventional synthetic 0079-6425/$ -see front matter Ó

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“…Seki et al (2005) demonstrated the viscoelastic response of the outer keratin layer of the toucan beak that comprises hexagonal scales glued together and the internal fibrous network of closed cells containing calcium-rich proteins. The keratin layer showed strain rate sensitivity with a transition from slippage of the scales owing to the release of organic glue, whereas the closed cell foam fibres displayed increased stiffness (approx.…”

mentioning

confidence: 99%

“…There has been considerable interest in correlating the multi-scale structure of biological systems (such as toucan beak, human hair, cartilage, bacteria) with their mechanical behaviour (Seki et al 2005;Wei & Bhushan 2006;Yuan & Verma 2006;Franke et al 2007;Wang et al 2007). Seki et al (2005) demonstrated the viscoelastic response of the outer keratin layer of the toucan beak that comprises hexagonal scales glued together and the internal fibrous network of closed cells containing calcium-rich proteins.…”

mentioning

confidence: 99%

Melanocyte pigmentation stiffens murine cardiac tricuspid valve leaflet

Balani

Brito

Kos

et al. 2009

J. R. Soc. Interface.

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Pigmentation of murine cardiac tricuspid valve leaflet is associated with melanocyte concentration, which affects its stiffness. Owing to its biological and viscoelastic nature, estimation of the in situ stiffness measurement becomes a challenging task. Therefore, quasi-static and nanodynamic mechanical analysis of the leaflets of the mouse tricuspid valve is performed in the current work. The mechanical properties along the leaflet vary with the degree of pigmentation. Pigmented regions of the valve leaflet that contain melanocytes displayed higher storage modulus (7 -10 GPa) than nonpigmented areas (2.5 -4 GPa). These results suggest that the presence of melanocytes affects the viscoelastic properties of the mouse atrioventricular valves and are important for their proper functioning in the organism.

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Structure and mechanical behavior of a toucan beak

Cited by 114 publications

References 25 publications

Multi-layered bird beaks: a finite-element approach towards the role of keratin in stress dissipation

Multi-layered bird beaks: a finite-element approach towards the role of keratin in stress dissipation

Biological materials: Structure and mechanical properties

Melanocyte pigmentation stiffens murine cardiac tricuspid valve leaflet

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