Multiscale Mechanics of Composite Hydrogels Exposed to Shock Waves

复合水凝胶暴露于冲击波的多尺度力学

• 批准号: 2114565
• 负责人: Jaime Juarez
• 金额: $ 54.88万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2114565&HistoricalAwards=false
• 关键词: Multiscale; Mechanics; Composite; Hydrogels; Exposed

This grant will support research to examine the response of hydrogels to shock waves, which is not well understood. A hydrogel (e.g. Jell-O, styling gel) is a material that consists of a water soluble polymer that can swell to form an interconnected three-dimensional network. Hydrogels have also been used as surrogate material for soft biological tissue due to their similarity in mechanical properties. The passage of a shock wave through hydrogels may serve as a model for investigating blast-induced traumatic brain injury as, for example, sustained by United States’ military service members. However, characterizing the mechanical response of shocked hydrogels is first needed. The project will test the hypothesis that the energy from shock waves disrupt the hydrogel network, leading to changes in hydrogel mechanical properties. An understanding of the behavior of shocked hydrogels would aid material scientists in developing tissue surrogate materials for blast studies, along with more resilient hydrogel formulations for wearable sensor and soft robot applications. Additionally, this research project will be complemented by engaging with existing organizations such as Iowa State University’s Academic Program for Excellence and the Program for Women in Science and Engineering. Initiatives that support the recruitment and retention of underrepresented students in the field of engineering will be established through outreach activities that introduce students to topics such as rheology and biomaterials.The specific goal of the research is to fundamentally understand the effect of shock wave exposure on the bulk and microstructural properties of composite hydrogels that act as tissue simulants. Molecular dynamic simulations of shock waves in hydrogels have shown a decrease in local concentration of water, leading to changes in bulk mechanical properties. However, experimental observations of hydrogel exposure to shock waves are needed for validation. Thus, the research objectives of this project include: (1) probing hydrogel microstructure at quasistatic conditions using optical video microscopy to measure viscoelastic behavior; (2) measurement of hydrogel mechanical response before and after shock wave exposure to connect microstructural changes to modified bulk mechanical behavior; and (3) quantification of the conformational changes of hydrogel due to shock wave exposure at the microstructural level. The overarching focus will be on the use of experiments to (i) obtain a better understanding of the macrostructural and microstructural changes that hydrogels undergo when exposed to a shock wave and (ii) correlating the structural changes with viscoelasticity behavior. This project will advance knowledge in mechanics and material science, along with computational science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项拨款将支持研究，以检查水凝胶对冲击波的反应，这是不太清楚。 水凝胶（例如Jell-O，定型凝胶）是由水溶性聚合物组成的材料，其可以溶胀以形成互连的三维网络。 水凝胶也被用作软生物组织的替代材料，因为它们在机械性能方面具有相似性。冲击波通过水凝胶的通道可以用作研究爆炸引起的创伤性脑损伤的模型，例如，由美国军事服务人员持续的。然而，首先需要表征冲击水凝胶的机械响应。该项目将测试冲击波能量破坏水凝胶网络，导致水凝胶机械性能变化的假设。对冲击水凝胶行为的了解将有助于材料科学家开发用于爆炸研究的组织替代材料，以及用于可穿戴传感器和软机器人应用的更具弹性的水凝胶配方，沿着。此外，这一研究项目将通过与现有组织，如爱荷华州州立大学的卓越学术计划和妇女在科学和工程计划的参与。通过向学生介绍流变学和生物材料等主题的外联活动，将建立支持工程领域代表性不足的学生的招聘和保留的举措。研究的具体目标是从根本上了解冲击波暴露对作为组织模拟物的复合水凝胶的体积和微观结构特性的影响。水凝胶中冲击波的分子动力学模拟表明，水的局部浓度降低，导致散装机械性能的变化。然而，需要对水凝胶暴露于冲击波的实验观察进行验证。因此，本计画的研究目标包括：（1）在准静态条件下，利用光学影像显微镜探讨水凝胶的微结构，以量测黏弹性行为;（2）量测水凝胶在冲击波暴露前后的力学反应，以将微结构的改变与改良的整体力学行为联系起来;和（3）在微观结构水平上定量由于冲击波暴露引起的水凝胶的构象变化。首要的重点将是使用实验，以（i）获得更好的理解的宏观结构和微观结构的变化，水凝胶暴露于冲击波和（ii）相关的结构变化与粘弹性行为。该项目将推动力学和材料科学知识的发展，沿着计算科学。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。