scispace - formally typeset
Search or ask a question
Author

Yasuaki Seki

Bio: Yasuaki Seki is an academic researcher from University of California, San Diego. The author has contributed to research in topics: Toco toucan & Ultimate tensile strength. The author has an hindex of 11, co-authored 13 publications receiving 2709 citations. Previous affiliations of Yasuaki Seki include University of California & University of California, Berkeley.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the basic building blocks are described, starting with the 20 amino acids and proceeding to polypeptides, polysaccharides, and polyprotein-saccharide.

2,074 citations

Journal ArticleDOI
TL;DR: Recent progress on studies of the abalone and Araguaia river clam shells, arthropod exoskeletons, antlers, tusks, teeth and bird beaks is reported on.
Abstract: Mineralized biological tissues offer insight into how nature has evolved these components to optimize multifunctional purposes. These mineral constituents are weak by themselves, but interact with the organic matrix to produce materials with unexpected mechanical properties. The hierarchical structure of these materials is at the crux of this enhancement. Microstructural features such as organized, layered organic/inorganic structures and the presence of porous and fibrous elements are common in many biological components. The organic and inorganic portions interact at the molecular and micro-levels synergistically to enhance the mechanical function. In this paper, we report on recent progress on studies of the abalone and Araguaia river clam shells, arthropod exoskeletons, antlers, tusks, teeth and bird beaks.

354 citations

Journal ArticleDOI
TL;DR: This work applies the power of advanced characterization, mechanical testing, and modeling methods to biomineralized shells, avian beaks and feathers, and fish scales, and presents a few selected bioinspired applications.
Abstract: The approach used by Materials Science and Engineering is revealing new aspects in the structure and properties of biological materials. The integration of advanced characterization, mechanical testing, and modeling methods can rationalize heretofore unexplained aspects of these structures. As an illustration of the power of this methodology, we apply it to biomineralized shells, avian beaks and feathers, and fish scales. We also present a few selected bioinspired applications: Velcro, an Al2O3-PMMA composite inspired by the abalone shell, and synthetic attachment devices inspired by gecko.

158 citations

Journal ArticleDOI
01 Jul 2006-JOM
TL;DR: In this article, the overall design principles in biological structural composites and illustrates them for five examples; sea spicules, the abalone shell, conch shell, the toucan and hornbill beaks, and the sheep crab exoskeleton.
Abstract: Biological materials are complex composites that are hierarchically structured and multifunctional. Their mechanical properties are often outstanding, considering the weak constituents from which they are assembled. They are for the most part composed of brittle (often, mineral) and ductile (organic) components. These complex structures, which have risen from millions of years of evolution, are inspiring materials scientists in the design of novel materials. This paper discusses the overall design principles in biological structural composites and illustrates them for five examples; sea spicules, the abalone shell, the conch shell, the toucan and hornbill beaks, and the sheep crab exoskeleton.

131 citations

Journal ArticleDOI
TL;DR: The structure of a Toco toucan (Ramphastos toco) beak was found to be a sandwich composite with an exterior of keratin and a fibrous network of closed cells made of calcium-rich proteins as discussed by the authors.

112 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: The common design motifs of a range of natural structural materials are reviewed, and the difficulties associated with the design and fabrication of synthetic structures that mimic the structural and mechanical characteristics of their natural counterparts are discussed.
Abstract: Natural structural materials are built at ambient temperature from a fairly limited selection of components. They usually comprise hard and soft phases arranged in complex hierarchical architectures, with characteristic dimensions spanning from the nanoscale to the macroscale. The resulting materials are lightweight and often display unique combinations of strength and toughness, but have proven difficult to mimic synthetically. Here, we review the common design motifs of a range of natural structural materials, and discuss the difficulties associated with the design and fabrication of synthetic structures that mimic the structural and mechanical characteristics of their natural counterparts.

3,083 citations

Journal ArticleDOI
TL;DR: In this paper, a review discusses the various attempts reported on solving this problem from the point of view of the chemistry and the structure of these polymers highlighting the drawbacks and advantages of each method and proposes that based on considerations of structure-property relations, it is possible to obtain chitin fibers with improved strength by making use of their nanostructures and/or mesophase properties of chitins.

2,278 citations

Journal ArticleDOI
TL;DR: In this paper, the basic principles involved in designing hierarchical biological materials, such as cellular and composite architectures, adapative growth and as well as remodeling, are discussed, and examples that are found to utilize these strategies include wood, bone, tendon, and glass sponges.

2,274 citations

Journal ArticleDOI
TL;DR: In this article, the basic building blocks are described, starting with the 20 amino acids and proceeding to polypeptides, polysaccharides, and polyprotein-saccharide.

2,074 citations

Journal ArticleDOI
05 Dec 2008-Science
TL;DR: In this article, the authors emulate Nature's toughening mechanisms through the combination of two ordinary compounds, aluminum oxide and polymethylmethacrylate, into ice-templated structures whose toughness can be over 300 times (in energy terms) that of their constituents.
Abstract: The notion of mimicking natural structures in the synthesis of new structural materials has generated enormous interest but has yielded few practical advances. Natural composites achieve strength and toughness through complex hierarchical designs extremely difficult to replicate synthetically. Here we emulate Nature's toughening mechanisms through the combination of two ordinary compounds, aluminum oxide and polymethylmethacrylate, into ice-templated structures whose toughness can be over 300 times (in energy terms) that of their constituents. The final product is a bulk hybrid ceramic material whose high yield strength and fracture toughness ({approx}200 MPa and {approx}30 MPa{radical}m) provide specific properties comparable to aluminum alloys. These model materials can be used to identify the key microstructural features that should guide the synthesis of bio-inspired ceramic-based composites with unique strength and toughness.

1,457 citations