Electrokinetics in Liquid Crystals

液晶动电学

• 批准号: 1507637
• 负责人: Oleg Lavrentovich
• 金额: $ 40万
• 依托单位: Kent State University
• 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 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507637&HistoricalAwards=false
• 关键词: Electrokinetics; Liquid; Crystals

Non Technical Abstract Liquid crystals (LCs) represent a peculiar state of matter combining properties of solid crystals and isotropic fluids. The subtle combination of orientational order, fluidity, and eager responsiveness to the electric field featured by the LCs brought a revolution in the way we present information nowadays, enabling an entire industry of portable LC displays. The project focuses on LCs as a functional medium that enables new forms of electrokinetics, i.e., motion of particles and fluids under an externally applied electric field. As compared to standard isotropic fluids such as water, the LCs offer new mechanisms of electrokinetics, rooted in orientational order of molecules. The project explores a new approach to induce and control the electrokinetic flows through surface-imprinted molecular orientation of the LC. The objective is to establish a fundamental understanding of electrokinetics in LCs, determine which new technologies and applications might emerge from the study, and to train the new generation of researcher (graduate students and postdoctoral fellows) in this cutting edge research of technological significance.Technical Abstract Electrokinetics represents a broad spectrum of phenomena associated with a relative motion at fluid/solid interfaces caused by external electric fields that act on suitably separated space charges, such as electric double layers or induced charges. The project goals are to explore a new mechanism of electrokinetics, in which the spatial charges are generated through the coupling of anisotropic electric conductivity to the liquid crystal (LC) director gradients and also to develop a new method to trigger the electrokinetic flows, through the imprinted surface patterns of director gradients. The control of surface alignment is performed locally in each point of the substrate by photo-irradiation. The project advances knowledge of electrohydrodynamics of isotropic fluids and electrohydrodynamics of LCs, two extremely rich scientific branches usually considered separately. It brings a new perspective in a general area of charge transport in organic matter which embraces photosynthesis, transport within proteins and across biomembranes. The project uses well-tested experimental methods such as three-dimensional optical microscopy, microparticle velocimetry, photoalignment and electro-optics, thus ensuring that the new knowledge is based on a solid experimental background. The research advances discovery and understanding of electrokinetics and LCs as materials for applications other than LC displays. The study offers new perspectives for practical applications where highly flexible, precise and simple control of fluid or cargo placement, delivery, mixing or sorting is needed. The research will be conducted at the Liquid Crystal Institute, which will immediately make the results and techniques available to numerous partners already linked together by the Institute's Industrial Partnership Program. The project helps to achieve the educational goals of the 5-Year Federal Science, Technology, Engineering, and Mathematics (STEM) Education Strategic Plan and the Materials Genome Initiative, by preparing the next generation of highly trained science professionals.

非技术摘要液晶（LC）代表了一种特殊的物质状态，结合了固体晶体和各向同性流体的性质。 液晶显示器所具有的取向有序性、流动性和对电场的强烈响应性的微妙结合，为我们当今呈现信息的方式带来了一场革命，使整个便携式液晶显示器行业成为可能。 该项目的重点是LC作为一种功能介质，使新形式的电动力学，即，颗粒和流体在外加电场下的运动。 与标准的各向同性流体如水相比，LC提供了新的电动力学机制，其根源在于分子的取向顺序。 该项目探索了一种新的方法来诱导和控制电动流动通过表面印迹分子取向的液晶。 目的是建立对LC电动力学的基本理解，确定哪些新技术和应用可能从研究中出现，并培养新一代的研究人员（研究生和博士后研究员）在这项前沿研究的技术意义。技术摘要电动力学代表了一个广泛的现象与相对运动的流体/由作用于适当分离的空间电荷（例如双电层或感应电荷）的外部电场引起的固体界面。 该项目的目标是探索一种新的电动力学机制，其中空间电荷是通过各向异性电导率与液晶（LC）指向矢梯度的耦合产生的，并开发一种新的方法来触发电动流动，通过指向矢梯度的压印表面图案。表面对准的控制通过光照射在基板的每个点中局部地执行。该项目推进了各向同性流体的电流体动力学和LC的电流体动力学的知识，这两个非常丰富的科学分支通常被单独考虑。 它带来了一个新的视角，在一般领域的电荷传输在有机物质，其中包括光合作用，运输内的蛋白质和跨生物膜。 该项目使用了经过充分测试的实验方法，如三维光学显微镜、微粒测速仪、光对准和电光，从而确保新知识建立在坚实的实验背景之上。该研究推进了电动力学和LC作为LC显示器以外的应用材料的发现和理解。 该研究为实际应用提供了新的视角，需要高度灵活，精确和简单地控制流体或货物的放置，交付，混合或分拣。这项研究将在液晶研究所进行，该研究所将立即向已经通过该研究所的工业伙伴关系计划联系在一起的众多合作伙伴提供研究结果和技术。 该项目通过培养下一代训练有素的科学专业人员，帮助实现5年期联邦科学、技术、工程和数学（STEM）教育战略计划和材料基因组计划的教育目标。