Key Lab of Bionic Engineering, Ministry of Education, Jilin University, Changchun, 130025, China.
Key Lab of Bionic Engineering, Ministry of Education, Jilin University, Changchun, 130025, China.
Micron. 2019 Nov;126:102735. doi: 10.1016/j.micron.2019.102735. Epub 2019 Aug 19.
The feathers of the seagull Larus argentatus are lightweight but can withstand high alternating stresses and exhibit excellent stiffness and strength. The shaft is an important part of the feather, with the functions of body protection and supporting flight. In this study, the microstructure properties of L. argentatus feather rachis were analysed by scanning electron microscopy (SEM). These analysis methods enabled the configuration, structure and compression properties of the rachis to be investigated. The results indicated that the rachis was composed of the outer cortex and the inner medulla. The cortex had a continuous layered nano-fibre composite structure, which bears, transmits, absorbs and disperses the compression force. The medulla had bubble-like cells with a porous-fibre structure, which rapidly absorbs, transmits and consumes compression force and is a suitably lightweight material for flight. Axial compression tests showed that the rachis from primary feathers had the best energy absorption and that from secondary feathers had the best compressive strength. The compressive strength might have something to do with the ratio of cortical area to medullary area. When the moisture content in the rachis increased, the compressive strength of feather rachis in different parts would decrease. These results indicate that the L. argentatus feather rachis have excellent compression resistance properties, deriving from structural factor.
海鸥 Larus argentatus 的羽毛重量轻，但能承受高交变应力，表现出优异的刚度和强度。羽轴是羽毛的重要组成部分，具有保护身体和支撑飞行的功能。本研究采用扫描电子显微镜（SEM）分析了海鸥羽毛羽轴的微观结构特性。这些分析方法可以研究羽轴的结构、压缩特性。结果表明，羽轴由外皮质和内髓质组成。皮质具有连续的层状纳米纤维复合材料结构，能够承受、传递、吸收和分散压缩力。髓质具有泡状细胞的多孔纤维结构，能迅速吸收、传递和消耗压缩力，是一种适合飞行的轻质材料。轴向压缩试验表明，初级羽毛的羽轴具有最佳的能量吸收能力，而次级羽毛的羽轴具有最佳的抗压强度。抗压强度可能与皮质面积与髓质面积的比值有关。当羽轴中的水分含量增加时，不同部位羽毛羽轴的抗压强度会降低。这些结果表明，海鸥羽毛羽轴具有优异的抗压性能，这源于结构因素。
