Mechanics of Deformation of Flexible Fibrous Networks

柔性纤维网络的变形力学

• 批准号: 1363135
• 负责人: Omar Saleh
• 金额: $ 40万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1363135&HistoricalAwards=false
• 关键词: Mechanics; Deformation; Flexible; Fibrous; Networks

Many useful materials are made up of interconnected networks of fibers. This is observed both in biological materials (such as tissues and cells) as well as in man-made materials (such as paper and textiles). Resistance to external forces is a key property of these materials. Still, it is not understood how the mechanical characteristics of the fibers and the distribution of the cross-links between fibers determine the stiffness of the entire network. Here, fibrous networks with precise control over network architecture will be created. These materials will then be tested mechanically. Thereby, this research will reveal exactly which microscopic parameters matter most in defining network stiffness. Specific results will test a recent predictive model of network mechanics and contribute to the fundamental understanding of the mechanical properties of biomaterials. General outcomes will influence the use of artificial fibrous materials, with potential impacts for the design of prosthetics and/or tissue implants. The Principal Investigators will contribute to human resource development in Science, Technology, Math and Engineering. The investigators will synthesize fibrous networks using sequence-based self-assembly of DNA, and test their mechanical properties using an array of methods of rheology. Networks will be designed using a two-component strategy in which linkers are attached to multi-armed nodes. As a result, it will be possible to independently vary the bend stiffness and stretch stiffness of the linkers, as well as the connectivity of the nodes. Investigation will focus on so-called "marginal gels" (i.e. networks whose connectivity is in the vicinity of the Maxwell isostatic point) that are predicted to have dramatic mechanical properties associated with thermodynamic critical behavior, including a sudden stiffening with connectivity, and critical fluctuations. College internship opportunities and through cross-disciplinary graduate student training will be provided. International collaboration via student exchanges and through an international summer workshop on biomolecular networks will be conducted.

许多有用的材料都是由相互连接的纤维网络构成的。这在生物材料（如组织和细胞）和人造材料（如纸张和纺织品）中都可以观察到。抗外力是这些材料的一个关键特性。然而，纤维的力学特性和纤维间交联的分布如何决定整个网络的刚度还不清楚。在这里，将创建对网络架构进行精确控制的纤维网络。然后将对这些材料进行机械测试。因此，本研究将揭示哪些微观参数在定义网络刚度时最重要。具体结果将测试网络力学的最新预测模型，并有助于对生物材料力学特性的基本理解。一般结果将影响人工纤维材料的使用，对假肢和/或组织植入物的设计有潜在影响。首席研究员将为科学、技术、数学和工程领域的人力资源发展作出贡献。研究人员将使用基于序列的DNA自组装合成纤维网络，并使用一系列流变学方法测试其机械性能。网络将采用双组件策略设计，其中连接器连接到多臂节点。因此，可以独立地改变连接件的弯曲刚度和拉伸刚度，以及节点的连通性。研究将集中在所谓的“边际凝胶”（即连通性在麦克斯韦等静力点附近的网络）上，这些网络被预测具有与热力学临界行为相关的戏剧性机械性能，包括连通性的突然硬化和临界波动。学院将提供实习机会并通过跨学科的研究生培训。将通过学生交换和生物分子网络国际夏季研讨会进行国际合作。