CAREER: Unveiling the Stability, Rheology, and Topology of Active Fluids

职业生涯：揭示活性流体的稳定性、流变性和拓扑结构

• 批准号: 1943759
• 负责人: Tong Gao
• 金额: $ 50万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1943759&HistoricalAwards=false
• 关键词: CAREER; Unveiling; Stability; Rheology; Topology

This CAREER award involves emerging field of active fluids, which are a new class of liquid materials made up of densely packed suspensions of particles that can propel themselves by converting energy from locally available fuel into locomotion. Active fluids hold great potential for the development of new materials and products, but realizing this potential requires a quantitative understanding of the unusual material properties and transport mechanisms that these fluids exhibit, which can be much different than the properties of suspensions of inert particles. This project will combine theoretical analysis and numerical simulations to build a holistic computation framework for modeling, analysis, and control of active fluids in complex microfluidic environments. The project will provide undergraduate and graduate student training, create K-12 outreach opportunities, and support the development of a Virtual Reality package that will help interpret research results and enrich classroom teaching. The Virtual Reality package and demos will be available online to the general public, along with some of the open-source computation codes developed in the project, which will benefit both students and researchers in applied science and engineering.The physical properties of active fluids are fundamentally different from those of classical equilibrium systems. When suspended in a liquid, motile microparticles exert stresses on the ambient flows, which acts as a coupling medium for generating large-scale, unsteady collective dynamics. These concentrated systems often show common features, including ordering transition, fluctuating density, and force generation. The research in this project will take the next engineering step of learning how to manipulate active fluids by taking full advantage of their collective behaviors. The project consists of four research thrusts: (1) Develop a hybrid algorithm that combines penetration-free Stokesian dynamics particle simulations and coarse-grained active liquid crystal models; (2) Study the hydrodynamic instabilities and coherent flows; (3) Investigate non-equilibrium rheological properties and topological structures; and (4) Design active-liquid metamaterials for novel engineering applications. The hybrid algorithm will follow a bottom-up multiscale approach. The microscale discrete particle dynamics will be used to construct continuum kinetic models and new "polar" active liquid crystal models. The computational framework will permit researchers and practitioners to control active fluids by adjusting particle activity and interactions at the microscale, and by controlling and guiding constrained coherent flows at the macroscale. The numerical studies, together with supporting experimental verifications, will lead to quantitative understandings of the linkages between dynamics across scales, and possibly to new engineering devices for transporting fluids and particles.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.

该职业奖涉及活跃的流体领域，这是一类新的液体材料，由密集包装的颗粒悬浮液组成，可以通过将能量从本地可用的燃料转化为运动来推动自己。活性流体具有巨大的新材料和产品的潜力，但是意识到这种潜力需要对这些流体所表现出的异常材料特性和运输机制有定量的理解，这可能与惰性颗粒悬浮液的特性大不相同。 该项目将结合理论分析和数值模拟，以构建一个整体计算框架，用于在复杂的微流体环境中对活动流体进行建模，分析和控制。该项目将提供本科生和研究生培训，创造K-12外展机会，并支持虚拟现实包的开发，该计划将有助于解释研究结果并丰富课堂教学。虚拟现实软件包和演示将在线向公众提供，以及项目中开发的一些开源计算代码，这将使应用科学和工程的学生和研究人员都受益。活动流体的物理特性与经典平衡系统的物理性质根本不同。当悬浮在液体中时，机动微粒会在环境流上施加应力，这是产生大规模，不稳定的集体动力学的耦合介质。这些集中系统通常显示出共同的特征，包括订购过渡，波动密度和力产生。该项目中的研究将采取下一个工程步骤来学习如何通过充分利用其集体行为来操纵活动流体。该项目由四个研究推力组成：（1）开发一种混合算法，该算法结合了无穿透性的Stokesian动力学粒子模拟和粗粒的活性液晶模型； （2）研究流体动力学不稳定性和相干流； （3）研究非平衡性流变特性和拓扑结构； （4）为新型工程应用设计主动液体材料。混合算法将遵循自下而上的多尺度方法。显微镜离散粒子动力学将用于构建连续动力学模型和新的“极性”活动液晶模型。该计算框架将使研究人员和从业人员通过调节微观的粒子活性和相互作用，以及控制和指导宏观的相干流，通过调节粒子活性和相互作用来控制活性流体。数值研究以及支持实验验证将导致对跨尺度动力学之间的联系的定量理解，甚至可能是用于运输流体和颗粒的新工程设备。这项奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和广泛的影响来评估CREITERIA的评估，以评估值得通过评估。

项目成果

Q -tensor model for undulatory swimming in lyotropic liquid crystal polymers

溶致液晶聚合物中波动游动的 Q 张量模型

• DOI: 10.1017/jfm.2021.531
• 发表时间: 2021
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Lin, Zhaowu;Chen, Sheng;Gao, Tong
• 通讯作者: Gao, Tong

Anisotropic swimming and reorientation of an undulatory microswimmer in liquid-crystalline polymers

液晶聚合物中波动微型游泳器的各向异性游泳和重新定向

• 发表时间: 2022
• 期刊: Journal of fluid mechanics
• 影响因子: 3.7
• 作者: Lin, Zhaowu;Yu, Zhaosheng;Li, Jinxing;Gao, Tong
• 通讯作者: Gao, Tong

Hydrodynamic instabilities of activity-balanced binary suspensions

活性平衡二元悬浮液的流体动力学不稳定性

• DOI: 10.1103/physrevfluids.7.063101
• 发表时间: 2022
• 期刊: Physical Review Fluids
• 影响因子: 2.7
• 作者: Palmer, Bryce;Yan, Wen;Gao, Tong
• 通讯作者: Gao, Tong

Understanding topological defects in fluidized dry active nematics

了解流化干活性向列相的拓扑缺陷

• DOI: 10.1039/d1sm01405f
• 发表时间: 2022
• 期刊: Soft Matter
• 影响因子: 3.4
• 作者: Palmer, Bryce;Chen, Sheng;Govan, Patrick;Yan, Wen;Gao, Tong
• 通讯作者: Gao, Tong

Scaling law of Brownian rotation in dense hard-rod suspensions

稠密硬棒悬浮液中布朗旋转的标度定律

• DOI: 10.1103/physreve.102.012608
• 发表时间: 2020
• 期刊: Physical Review E
• 影响因子: 2.4
• 作者: Chen, Sheng;Yan, Wen;Gao, Tong
• 通讯作者: Gao, Tong