Collective Hydrodynamics of Swimming Bacteria: A Living Fluid

游动细菌的集体流体动力学:一种活体液体

基本信息

  • 批准号:
    0730579
  • 负责人:
  • 金额:
    $ 24万
  • 依托单位:
  • 依托单位国家:
    美国
  • 项目类别:
    Continuing Grant
  • 财政年份:
    2007
  • 资助国家:
    美国
  • 起止时间:
    2007-08-01 至 2011-07-31
  • 项目状态:
    已结题

项目摘要

National Science Foundation - Division of Chemical &Transport Systems ? Particulate & Multiphase Processes Program (1415)Proposal Number: 0730579 Principal Investigators: Koch, Donald Affiliation: Cornell University Proposal Title: Collective Hydrodynamics of Swimming Bacteria: A Living Fluid Suspensions of swimming micro-organisms such as the bacterium E. coli constitute a unique type of non-Newtonian fluid that can exhibit a negative-viscosity instability, enhanced mixing by secondary flows resulting from a negative first normal stress difference, break up due to concentration-gradient-induced stresses, and migration phenomena that facilitate novel separation methods. While the physical mechanism by which a single bacterium swims, pushing itself through the fluid with a flagella bundle that turns like a screw, is well understood, the equations of motion governing a suspension of bacteria have not been derived previously. In the proposed study, we will derive these equations starting from a fundamental description of bacteria-fluid interactions, solve the equations for several representative flows, and observe these flows experimentally. Intellectual Merit: A bacteria cell exerts a drag force on the fluid while its flagella exert an equal and opposite force, leading to a force dipole which on average creates a pressure in the direction of mean cell orientation. This situation may be contrasted with a stretched polymer which exerts a tension in the direction of its orientation. In a weak shear flow, a bacterium orients with the extensional axis of the flow and reinforces the extensional motion. Thus, above a critical cell concentration, the suspension has a negative viscosity and a quiescent suspension will be unstable to the formation of spontaneous fluid motion. We believe that this instability explains previous experimental observations of vortical motions in systems of swimming bacteria. We plan to use particle tracking of both bacteria and passive colloidal particles to probe this instability. The alignment of bacteria along streamlines in a strong shear flow will create a negative first normal stress difference (or streamline pressure) in contrast to the positive first normal stress difference (or streamline tension) for polymer solutions. Both non-Newtonian fluids can enhance mixing due to secondary flows caused by streamline curvature in a curved microfluidic channel, but, as we shall confirm, the vortices will be centered on the inside of a channel bend for bacteria and on the outside for a polymer solution. Broader Impacts: The applications of our studies include a novel method to separate bacteria based on their chemotactic behavior, a new ?active? fluid for micro-fluidic mixing whose activity can be modulated by biochemical inputs, and insights into the manner in which cells disperse or collect themselves into clusters as they respond to biochemical cues. People have a natural curiosity about the collective behavior of living things. Our studies which link such collective behaviors to the principles of momentum and mass transport and kinetic theory descriptions of suspensions will provide a means to engage and inspire students to think about connections between biology and engineering. We will exploit these opportunities in our undergraduate and graduate curricula and in the Nanobiotechnology Center's outreach program for high school teachers.
美国国家科学基金会化学与运输系统分部?微粒和多相过程计划(1415)提案编号:0730579主要研究者:Koch, Donald隶属关系:康奈尔大学提案标题:游泳细菌的集体流体动力学;游动微生物(如大肠杆菌)的悬浮液构成了一种独特的非牛顿流体,它可以表现出负粘度不稳定性,负第一正应力差导致的二次流增强混合,浓度梯度诱导的应力导致的破裂,以及有利于新型分离方法的迁移现象。虽然单个细菌游动的物理机制——借助像螺丝钉一样转动的鞭毛束推动自己穿过液体——已经被很好地理解了,但控制细菌悬浮的运动方程以前还没有推导出来。在本研究中,我们将从对细菌-流体相互作用的基本描述出发,推导出这些方程,求解几个代表性流动的方程,并通过实验观察这些流动。智力优势:细菌细胞对液体施加阻力,而它的鞭毛施加相等且相反的力,导致力偶极子,平均在细胞平均方向上产生压力。这种情况可以与拉伸聚合物形成对比,拉伸聚合物在其取向方向上施加张力。在弱剪切流中,细菌随流动的伸展轴定向并加强伸展运动。因此,在临界细胞浓度以上,悬浮液粘度为负,静止悬浮液将不稳定,形成自发的流体运动。我们相信,这种不稳定性解释了先前在游动细菌系统中对涡旋运动的实验观察。我们计划使用细菌和被动胶体粒子的粒子跟踪来探测这种不稳定性。在强剪切流中,细菌沿着流线排列将产生负的第一法向应力差(或流线压力),而聚合物溶液的第一法向应力差(或流线张力)为正。这两种非牛顿流体都可以增强混合,因为在弯曲的微流体通道中流线曲率引起的二次流动,但是,正如我们将确认的那样,漩涡将集中在通道弯曲的内部,而在外部对于聚合物溶液。更广泛的影响:我们的研究应用包括一种基于细菌趋化行为分离细菌的新方法,一种新的活性?用于微流体混合的流体,其活性可以通过生化输入来调节,并深入了解细胞在响应生化线索时分散或聚集成簇的方式。人们对生物的集体行为有一种天然的好奇心。我们的研究将这种集体行为与动量和质量传递原理以及悬浮的动力学理论描述联系起来,这将提供一种吸引和激励学生思考生物学和工程学之间联系的方法。我们将在我们的本科和研究生课程以及纳米生物技术中心的高中教师拓展计划中利用这些机会。

项目成果

期刊论文数量(0)
专著数量(0)
科研奖励数量(0)
会议论文数量(0)
专利数量(0)

数据更新时间:{{ journalArticles.updateTime }}

{{ item.title }}
{{ item.translation_title }}
  • DOI:
    {{ item.doi }}
  • 发表时间:
    {{ item.publish_year }}
  • 期刊:
  • 影响因子:
    {{ item.factor }}
  • 作者:
    {{ item.authors }}
  • 通讯作者:
    {{ item.author }}

数据更新时间:{{ journalArticles.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ monograph.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ sciAawards.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ conferencePapers.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ patent.updateTime }}

Donald Koch其他文献

Donald Koch的其他文献

{{ item.title }}
{{ item.translation_title }}
  • DOI:
    {{ item.doi }}
  • 发表时间:
    {{ item.publish_year }}
  • 期刊:
  • 影响因子:
    {{ item.factor }}
  • 作者:
    {{ item.authors }}
  • 通讯作者:
    {{ item.author }}

{{ truncateString('Donald Koch', 18)}}的其他基金

Slender body theory and finite difference computations to characterize particle-fluid interactions at moderate Reynolds numbers
细长体理论和有限差分计算来表征中等雷诺数下的颗粒-流体相互作用
  • 批准号:
    2206851
  • 财政年份:
    2022
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
The Effect of Particle-polymer Interactions on the Rheology and Structure of Dilute Particle-filled Polymeric Liquids
颗粒-聚合物相互作用对稀颗粒填充聚合物液体流变学和结构的影响
  • 批准号:
    1803156
  • 财政年份:
    2018
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
UNS: Employing hydrodynamic lift and particle trajectory ratcheting to achieve sieve-free separations based on size and shape in cross-flow filtration
UNS:利用流体动力升力和颗粒轨迹棘轮,在错流过滤中根据尺寸和形状实现无筛分离
  • 批准号:
    1505795
  • 财政年份:
    2015
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
Using shape to control the orientations and positions of particles in processing flows
使用形状来控制处理流程中颗粒的方向和位置
  • 批准号:
    1435013
  • 财政年份:
    2014
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
Collaborative Research: The role of microphysical processes and turbulence intermittency in droplet coalescence in warm cumulus clouds
合作研究:微物理过程和湍流间歇性在暖积云中液滴合并中的作用
  • 批准号:
    1435953
  • 财政年份:
    2014
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
Hydrodynamic instabilities and flow modification caused by preferential concentration of inertial particles
惯性颗粒优先集中引起的水动力不稳定性和流动改变
  • 批准号:
    1233793
  • 财政年份:
    2012
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
Hydrodynamically Assisted Bacterial Chemotaxis
流体动力学辅助细菌趋化作用
  • 批准号:
    1066193
  • 财政年份:
    2011
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
The Effects of Fluid-Particle and Particle-Particle Interactions on the Structure and Flow Properties of Suspensions of Fibers and Disks
流体-颗粒和颗粒-颗粒相互作用对纤维和圆盘悬浮液结构和流动性能的影响
  • 批准号:
    0332902
  • 财政年份:
    2004
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
Nonlinear-Flow-Induced Structure in Fiber Suspensions
纤维悬浮液中的非线性流动诱导结构
  • 批准号:
    9910908
  • 财政年份:
    2000
  • 资助金额:
    $ 24万
  • 项目类别:
    Continuing Grant
Fluid Flow, Pressure Drop, and Heat and Mass Transfer in Packed Beds at Moderate Reynolds Numbers
中等雷诺数下填充床中的流体流动、压降以及传热传质
  • 批准号:
    9526149
  • 财政年份:
    1996
  • 资助金额:
    $ 24万
  • 项目类别:
    Continuing Grant

相似国自然基金

基于Hydrodynamics-Reaction Kinetics耦合模型的厌氧膨胀床反应器三相流场数值模拟及生态-水力响应机制解析
  • 批准号:
    51078108
  • 批准年份:
    2010
  • 资助金额:
    36.0 万元
  • 项目类别:
    面上项目

相似海外基金

Hydrodynamics of quantum fluids
量子流体的流体动力学
  • 批准号:
    DP240101033
  • 财政年份:
    2024
  • 资助金额:
    $ 24万
  • 项目类别:
    Discovery Projects
Elucidating Hydrodynamics at Confined Interfaces for Artificial Active Fluidics and Beyond
阐明人工主动流体学及其他领域的受限界面处的流体动力学
  • 批准号:
    MR/X03660X/1
  • 财政年份:
    2024
  • 资助金额:
    $ 24万
  • 项目类别:
    Fellowship
CAREER: Collective hydrodynamics within viscous interfaces: activity and assembly in membranes and monolayers
职业:粘性界面内的集体流体动力学:膜和单层中的活性和组装
  • 批准号:
    2340415
  • 财政年份:
    2024
  • 资助金额:
    $ 24万
  • 项目类别:
    Continuing Grant
The development of new Smoothed Particle Hydrodynamics algorithm for dynamic fracture
用于动态断裂的新平滑粒子流体动力学算法的开发
  • 批准号:
    2894121
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    Studentship
RII Track-4:NSF: Enhanced Multiscale Approaches for Simulations of Multicomponent Fluids with Complex Interfaces using Fluctuating Hydrodynamics
RII Track-4:NSF:使用脉动流体动力学模拟具有复杂界面的多组分流体的增强多尺度方法
  • 批准号:
    2346036
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    Standard Grant
Time-Dependent Hydrodynamics in Uniform Fermi Gases
均匀费米气体中的瞬态流体动力学
  • 批准号:
    2307107
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    Continuing Grant
Clarification of Energy Mechanisms in Supercritical Accretion Flows on to Neutron Stars through Hydrodynamics and Radiative Transfer Simulations
通过流体动力学和辐射传输模拟阐明中子星超临界吸积流的能量机制
  • 批准号:
    22KJ0368
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    Grant-in-Aid for JSPS Fellows
NSF-BSF: The Evolution of Hydrodynamics, Mechanics, & Prey Capture in the Feeding of Misfit Fish
NSF-BSF:流体动力学、力学、
  • 批准号:
    2326484
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    Continuing Grant
Advanced hydrodynamics for next generation of offshore infrastructure
下一代海上基础设施的先进流体动力学
  • 批准号:
    FT230100109
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    ARC Future Fellowships
The interaction of waves with seaweed farms: wave attenuation and intra-farm hydrodynamics
波浪与海藻养殖场的相互作用:波浪衰减和养殖场内的流体动力学
  • 批准号:
    2888992
  • 财政年份:
    2023
  • 资助金额:
    $ 24万
  • 项目类别:
    Studentship
{{ showInfoDetail.title }}

作者:{{ showInfoDetail.author }}

知道了