CAREER: In- and Out-of-Equilibrium Behavior of Colloidal Clusters with Broken Symmetries

职业：对称性破缺的胶体团簇的平衡态和非平衡态行为

• 批准号: 1454095
• 负责人: Ning Wu
• 金额: $ 54.84万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1454095&HistoricalAwards=false
• 关键词: CAREER; Out; Equilibrium; Behavior; Colloidal

Colloidal dispersions play an important role in materials processing for industries ranging from electronics to pharmaceuticals. When colloidal particles are organized into arrays and other structures, the resulting materials can exhibit optical and electrical properties that are not found in natural materials. Therefore, colloids serve as building blocks for fabricating advanced functional materials. This project will develop new approaches to make clusters of colloidal particles with well-controlled compositions and geometries, which will expand the range of materials that can be fabricated. The project will investigate how external fields can be used to manipulate the assembly of particles into clusters and ultimately into large ensembles. Results from the project will provide fundamental knowledge that scientists and engineers can use to develop materials and devices, such as new sensors or new coatings with controlled optical properties. In addition, the project team will develop a summer research program in colloidal science targeted to high school students in the Denver area and especially to students from underrepresented groups. A multi-disciplinary course titled "Engineering of Soft Materials" will be developed to engage undergraduate students in colloidal science and train them for careers in the materials industry. New approaches will be developed to make clusters of colloids with well-controlled broken symmetries. A microfluidic device that integrates both electric (for assembly) and optical fields (for structural cross-linking) will be used to fabricate monodisperse higher order colloidal clusters with addressable compositions and geometries. The asymmetric properties of colloidal clusters will be systematically studied within the context of particle propulsion, which constitutes a significant step toward understanding the transport properties of active colloids. A virtually patterned electrode will be used to generate micro-gradients in electric field and direct particles into periodic structures with addressable symmetry at both cluster and lattice levels. The coupled optical effects between neighboring clusters and the feasibility for making functional coatings will also be explored. The overall goal of the project is to understand how the broken-symmetry in colloidal clusters affects their in- and out-of-equilibrium behavior from the level of an individual particle to a large ensemble.

胶体分散体在从电子到制药等行业的材料加工中发挥着重要作用。当胶体颗粒组织成阵列和其他结构时，所得材料可以表现出天然材料所没有的光学和电学特性。因此，胶体可以作为制造先进功能材料的基础材料。该项目将开发新方法来制造具有良好控制的成分和几何形状的胶体颗粒簇，这将扩大可制造的材料范围。 该项目将研究如何使用外部场来操纵粒子组装成簇并最终组装成大型集合体。 该项目的结果将提供科学家和工程师可用来开发材料和设备的基础知识，例如具有受控光学特性的新传感器或新涂层。 此外，项目团队还将针对丹佛地区的高中生，特别是来自弱势群体的学生，制定一个胶体科学夏季研究计划。 将开发一门名为“软材料工程”的多学科课程，以吸引本科生学习胶体科学，并培训他们在材料行业的职业生涯。 将开发新方法来制造具有良好控制的破缺对称性的胶体簇。集成电场（用于组装）和光场（用于结构交联）的微流体装置将用于制造具有可寻址成分和几何形状的单分散高阶胶体簇。将在粒子推进的背景下系统地研究胶体团簇的不对称特性，这构成了理解活性胶体的输运特性的重要一步。虚拟图案电极将用于在电场中产生微梯度，并将粒子引导到在簇和晶格水平上具有可寻址对称性的周期性结构中。还将探讨相邻簇之间的耦合光学效应以及制作功能涂层的可行性。该项目的总体目标是了解胶体团簇中的对称性破缺如何影响其从单个粒子到大集合的平衡和失衡行为。

项目成果

Reconfigurable microbots folded from simple colloidal chains

由简单胶体链折叠而成的可重构微型机器人

• DOI: 10.1073/pnas.2007255117
• 发表时间: 2020-07-17
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Tao Yang;Brennan Sprinkle;Yang Guo;Jun Qian;D. Hua;A. Donev;D. Marr;Ning Wu
• 通讯作者: Ning Wu