相关实验视频
Updated: Jul 17, 2025
09:47
Microdissection of Black Widow Spider Silk-producing Glands
Published on: January 11, 2011
15.8K
在加载-卸载周期和结构内涵中,蜘蛛大 ampullate丝的记忆效应和结构内涵
Ping Jiang1, Li-Hua Wu2, Tai-Yong Lv3
1Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Eco-environment and Resources, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi Province, 343009, China.
Journal of the mechanical behavior of biomedical materials
|August 28, 2023
概括
蜘蛛丝表现出了非凡的机械记忆,在拉伸后恢复到原来的拉伸行为,即使有很长的恢复间隔. 这一特性对于仿生材料设计至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 生物材料工程 生物材料工程
- 织科学 织科学
背景情况:
- 蜘蛛丝在生物功能过程中经历了反复的拉伸,与纤维形状变化和机械性能密切相关.
- 在重复拉伸后,变形和恢复时间对蜘蛛丝结构和拉伸行为的影响尚未得到充分理解.
研究的目的:
- 为了研究变形和间隔时间在重复拉伸后对主要囊丝 (MAS) 的结构和拉伸行为的影响.
- 了解蜘蛛丝的机械记忆和恢复机制.
主要方法:
- 在MAS上进行了一系列装载-卸载测试.
- 对真实应力-真实应变曲线的分析,以评估机械参数的演变与周期号.
- 在不同的拉伸和间隔时间后,研究恢复行为.
主要成果:
- 在短时间间隔 (8秒到5分钟) 后,MAS将独立于加载历史的拉伸行为逆转.
- 超出某种应变值的真压力-真应变曲线是历史独立的.
- 即使在长时间间隔 (≥1h) 之后,MAS也可以在一次拉伸后重现其最后的拉伸行为.
- 弹性模块随着应变而增加,而产量应力在循环中显示边际变化.
结论:
- 蜘蛛丝具有机械记忆,使其能够恢复到基本状态并表现出可预测的拉伸性能.
- 在弹性区域以外的拉伸行为中观察到可逆变化,归因于粘性弹性和组合变形机制.
- 这些发现为生物模拟设计的新型纤维材料提供了洞察力,这些材料受到蜘蛛丝腺的启发.
相关概念视频
01:21Plastic Behavior
222
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and...
222
01:18Residual Stresses in Bending
205
In the study of elastoplastic members subjected to bending moments, understanding the loading and unloading phases is crucial for assessing material behavior and structural integrity. During the loading phase, as the bending moment increases, the material initially responds elastically, adhering to Hooke's Law, where stress is directly proportional to strain. When the load exceeds the yield strength, plastic deformation occurs, resulting in permanent strain and deformation that remains even...
205
01:19Impact Loading
226
Impact loading occurs when a moving object collides with a stationary structure, such as a rod with a uniform cross-sectional area fixed at one end. Under these conditions, the rod absorbs the kinetic energy from the striking object, leading to deformation and subsequent stress development. As the rod returns to its original position and reaches maximum stress, the absorbed energy, initially manifested as kinetic energy, transforms entirely into strain energy.
In cases of elastic deformation,...
In cases of elastic deformation,...
226
01:35Disassembly of Intermediate Filaments
2.1K
Intermediate filaments (IFs) do not undergo spontaneous disassembly. Enzymes, kinases, and phosphatases add and remove phosphates from specific sites to regulate their disassembly. The IF concentration in the cytoplasm also regulates the disassembly. If the concentration crosses a threshold, it activates the protein kinases in the vicinity, allowing the phosphorylation of IFs.
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
2.1K
01:21Fatigue
206
Fatigue occurs when materials rupture under repeated or fluctuating loads, even at stress levels far below their static breaking strength. It typically results in brittle failure, even for ductile materials. It is a critical consideration in designing machines and structural components subjected to repetitive or varying loads. The nature of these loadings can range from fluctuating loads like unbalanced pump impellers causing vibrations to repeatedly bending a thin steel rod wire back and forth...
206
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
290
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
290