烏賊骨板之結構與機械性質設計研究

On the structural and mechanical design of cuttlebone(Speia pharaonis)

古堯天(Yao-Tien Ku)

指導教授 ： 陳柏宇

國立清華大學/工學院/材料科學工程學系/碩士(2013年)

https://doi.org/10.6843/NTHU.2013.00026

摘要

烏賊骨板是堅固的浮力控制裝置，能使烏賊輕易地在海水中維持固定的位置。它必須能承受靜水壓力，同時重量必須夠小以獲得足夠的浮力。在本研究中，我們探討虎斑烏賊(Sepia pharaonis)骨板的結構與機械性質。骨板微結構的特徵以立體顯微鏡、X光斷層掃描技術以及電子顯微鏡觀察之。骨板具有獨特的孔隙結構，其化學成分90%以上由碳酸鈣所組成，其餘的有機物為幾丁質與蛋白質。平行而層狀堆疊的薄板之間由許多薄壁支撐，每層薄板的間距由200微米到400微米不等，立體顯微鏡的鑑定顯示出，薄板間距呈現由腹部增加到背部的趨勢。於每個腔室中，許多有機薄膜位於薄壁之間。藉由對乾燥、新鮮的試片進行三種方向的壓縮測試: 平行薄板、垂直薄板以及與薄板夾45度角的施力方向量測骨板之機械性質。結果顯示薄板展現比薄壁優越的機械性質，機械性質呈現異向性質。在不同程度變形後的試片以電子顯微鏡、X光斷層掃描技術分別觀察表面與內部結構形貌，進而探討於骨板孔隙結構的變形機制。我們亦研究構成骨板的有機物以及無機物在力學上扮演的角色，結果顯示骨板的強度由兩者的相輔相成貢獻而得。此研究成果可進一步應用於設計新型仿生複合材料或生醫領域 。

關鍵字

生物陶瓷 ； 複合結構 ； 微結構 ； 機械性質 ； 仿生材料

並列摘要

The cuttlebone is a rigid buoyancy control device which enables the cuttlefish to maintain a fixed position in water with minimal effort. It must be strong enough to withstand hydrostatic pressure and lightweight in order not to sacrifice buoyancy. In this study, structure and mechanical properties of cuttlebone obtained from Sepia pharaonis were investigated. Micro-structural features of cuttlebone were characterized by stereoscope, micro-CT, and SEM. The cuttlebone, mainly made of CaCO3 in aragonite form and chitin, had a unique cellular architecture. Parallel lamellae called septum and supporting walls named pillars formed chambers with spacing varying from 200 to 400 μm. Numerous thin organic sheets between pillars within a chamber were observed. Mechanical properties were evaluated by compression tests on dry, rehydrated and fresh samples in three loading directions – parallel, perpendicular, and 45 degree to the septums. Results showed septums exhibit superior mechanical properties orientations compared with pillars. Deformed samples were examined by micro-CT and SEM at progressive stages and deformation mechanisms were evaluated. The role of mineral and organic component of cuttlebone played in the mechanical property was evaluated by deproteinization and demineralization. The results showed strong synergistic effect between the two constituents in the strength of cuttlebone. This investigation could further lead to the design of novel bio-inspired composites and biomedical applications.

並列關鍵字

bioceramics ； composites ； microstructure ； mechanical properties ； bio-inspired materials

參考文獻

[1] Ashby MF, Gibson LJ, Wegst U, Olive R. The mechanical-properties of natural materials .1. material property charts. Proceedings of the Royal Society-Mathematical and Physical Sciences. 1995;450:123-40.

[2] Gibson LJ. The hierarchical structure and mechanics of plant materials. J R Soc Interface. 2012;9:2749-66.

[3] Seki Y, Schneider M, Meyers M. Structure and mechanical behavior of a toucan beak. Acta Materialia. 2005;53:5281-96.

[4] Denton EJ, Gilpinbrown JB. Buoyancy of cuttlefish, Sepia officinalis (L). Journal of the Marine Biological Association of the United Kingdom. 1961;41:319-&.

[5] Denton EJ, Gilpinbrown JB. Distribution of gas and liquid within cuttlebone. Journal of the Marine Biological Association of the United Kingdom. 1961;41:365-&.