Emergent Behaviors of Dense Active Suspensions Under Shear

剪切下致密主动悬架的突现行为

• 批准号: 2327094
• 负责人: Itai Cohen
• 金额: $ 70.91万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327094&HistoricalAwards=false
• 关键词: Emergent; Behaviors; Dense; Active; Suspensions

Non-Technical AbstractThe flow of dense suspensions comprised of microscopic particles in solution is important to a variety of industrial processes ranging from 3D printing to polishing of semiconductor components. This project seeks to develop a new knob for manipulating the flow of such materials. In particular, it is proposed that particle activity, i.e. using electric fields to inject energy in the form of particle rotations or other motions at the single particle level, can be developed into a novel knob for manipulating the properties of flowing suspensions. The work capitalizes on a novel combination experimental, simulation, and theory techniques developed by the PIs to map out the range of behaviors that activity in flowing suspensions can induce and determine the underlying organization of the suspended particles that drives these changes to the flow. In addition to these technological impacts, a number of education and outreach activities are proposed including science communication workshops, participation in research experience for undergraduate summer activities, and various outreach activities to the broader public.Technical AbstractActive matter has become a major branch of statistical mechanics where energy, rather than being conserved, is pumped into the system at the particle level. One of the great anticipated potentials of synthetic active materials is the ability to tune their macroscopic bulk properties through control of the microscopic interactions governing their constituents. To date, however, most active systems have been limited in their manufacturing scalability making it difficult to investigate bulk properties. This project capitalizes on the development of new Quincke rotor active systems that enable the investigation of the effect of activity on the bulk rheological properties of suspensions. The proposed work focuses on the effects of activity in the dense 3D regime since this is the regime where particles couple most strongly with one another and with the flow. In particular, it aims to determine how activity alters the rheological properties of suspensions including shear thickening and jamming transitions. Specifically, it is proposed to use experiments, simulations, and theory to determine: 1) how activity alters the shear behavior (e.g. thickening) of dense suspensions; 2) how the active particle interactions affect formation of mesoscale load bearing structures, and 3) how the force networks driving these behaviors are organized spatially. These investigations will provide a new knob, activity, for tuning the rheological behaviors of suspensions, an important material system for processes ranging from 3D printing, to polishing in semiconductor processes. In addition to these technological impacts, a number of education and outreach activities are proposed including science communication workshops, participation in research experience for undergraduate activities, and various outreach activities.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.

由溶液中的微观颗粒组成的致密悬浮液的流动对于从3D打印到半导体元件抛光的各种工业过程都很重要。该项目旨在开发一种新的旋钮，用于操纵此类材料的流动。特别地，提出了粒子活动，即使用电场以粒子旋转或在单个粒子水平上的其他运动的形式注入能量，可以发展成用于操纵流动悬浮液的性质的新颖旋钮。这项工作利用了PI开发的一种新颖的实验，模拟和理论技术相结合，以绘制出流动悬浮液中的活动可以诱导和确定悬浮颗粒的潜在组织的行为范围，这些组织驱动这些变化。除了这些技术的影响，一些教育和推广活动，建议包括科学交流研讨会，参与本科生暑期活动的研究经验，和各种推广活动，以更广泛的public.Technical AbstractActive物质已成为一个主要的分支的统计力学的能量，而不是被保存，被泵入系统中的粒子水平。合成活性材料的巨大预期潜力之一是通过控制控制其组分的微观相互作用来调节其宏观本体性质的能力。然而，迄今为止，大多数主动系统的制造可扩展性都受到限制，因此很难研究批量性能。该项目利用新的昆克转子主动系统的开发，使活动的影响悬浮液的散装流变性能的调查。拟议的工作集中在密集的3D政权的活动的影响，因为这是政权的粒子耦合最强烈的彼此和流动。特别是，它旨在确定活动如何改变悬浮液的流变特性，包括剪切增稠和堵塞转变。具体而言，建议使用实验、模拟和理论来确定：1）活性如何改变稠密悬浮液的剪切行为（例如增稠）; 2）活性颗粒相互作用如何影响介观承载结构的形成;以及3）驱动这些行为的力网络如何在空间上组织。这些研究将为调整悬浮液的流变行为提供一种新的方法，悬浮液是从3D打印到半导体工艺抛光的重要材料系统。除了这些技术影响之外，还提出了一些教育和推广活动，包括科学传播研讨会，参与本科生活动的研究经验，以及各种推广活动。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。