NSF/DMR-BSF: Liquid Crystals as a Paradigm for Chirality and Topological Defects

NSF/DMR-BSF：液晶作为手性和拓扑缺陷的范例

• 批准号: 1901797
• 负责人: Charles Rosenblatt
• 金额: $ 49.69万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1901797&HistoricalAwards=false
• 关键词: NSF; DMR; BSF; Liquid; Crystals

Nontechnical Abstract:Chirality is the inability of an object to coincide with its mirror image, where the left and right hands are perhaps the best-known example. A topological defect occurs when the system's inherent "character", scientifically called its "order parameter", cannot be described uniquely at a point, line, or surface. Both phenomena are pervasive throughout nature, often are coupled, and are fundamental to central questions in science and technology. A few examples include chirality in quantum optics, semiconductor diodes, and biomaterials - DNA is the best known; chirality transfer, i.e., how chirality can be induced in an otherwise non-chiral materials; and interactions of multiple topological defects. This project focuses on chirality and topological defects using liquid crystals as a paradigm. Because of the long length scales and novel optical properties of liquid crystals, many of the associated phenomena can be visualized and measured quantitatively. This permits a general understanding of chirality and topological defects that would not be possible by studying other materials.Technical Abstract:Owing to their large optical, electrical, and magnetic anisotropies, liquid crystals are an ideal test bed for a multitude of phenomena in condensed matter and beyond. The central theme of this work is to exploit liquid crystals to explore seminal issues of chirality and topological defects that can impact the broader scientific enterprise. The PI utilizes his nanoscale techniques to create and image controlled chirality and defects at surfaces - sometimes in combination. Projects include: chirality transfer in biologically-relevant chiral nanocapsules to achieve the Holy Grail, viz., a measure of the chiral induction length; the creation of chiral multipoles; chiral topological defects, induced biaxiality, and skyrmions; multistable "rewiring" of line defects; chiral self-assembled monolayers for nanophotonics and semiconductors; and highly complex oily and soapy streak liquid crystalline defects. The PI's team employs a battery of experimental tools, including optical microscopy, confocal fluorescence microscopy, optical nanotomography, atomic force microscopy, AFM nanolithography, and ellipsometry. Much of the work is performed in collaboration with chemist Prof. David Avnir and his colleagues at the Hebrew University of Jerusalem. By exploiting the PI's ability to create exquisitely tailored nano-scale chiral and topological defect easy axis patterns, and to image liquid crystal orientation down to x,y,z dimensions of 50 x 50 x 2 nm, this work is transforming our conceptions about - and methodology toward - chirality, defects, how the two can be coupled in anisotropic fluids, and broader issues in condensed matter. In particular, the PI's work is leading to the understanding, quantification, and exploitation of induced chirality in otherwise achiral materials, as well as a deeper knowledge of chiral and achiral topological defects, their manipulation, and potential applications in optics and electronics. The issues studied cut across multiple disciplines, as consequences of chirality and defects appear throughout biology, chemistry, physics, medicine, pharmacology, and materials science.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.

非技术摘要：手性是对象与镜像相吻合的对象，左手和右手可能是最著名的例子。 当系统固有的“字符”（科学称为其“顺序参数”）不能在某个点，线或表面上唯一描述时，就会发生拓扑缺陷。 两种现象在整个自然界都普遍存在，通常是耦合的，并且是科学和技术中的核心问题。 一些例子包括量子光学，半导体二极管和生物材料的手性 - DNA是最著名的；手性转移，即如何在原本非手续材料中诱导手性；以及多个拓扑缺陷的相互作用。 该项目的重点是使用液晶作为范式的手性和拓扑缺陷。 由于液晶的长度尺度和新颖的光学特性，许多相关现象可以被定量地可视化和测量。 这允许对手性和拓扑缺陷的一般理解，而这些缺陷是无法通过研究其他材料而无法实现的。技术摘要：由于它们的较大的光学，电气和磁各向异性，液晶是用于凝结物质及其他多种现象的理想测试床。这项工作的中心主题是利用液晶来探索手性和拓扑缺陷的开创性问题，这些缺陷可能会影响更广泛的科学企业。 PI利用他的纳米级技术来创建和图像控制的手性，并在表面上存在缺陷 - 有时是结合的。 项目包括：与生物学上的手性手性纳米胶囊中的手性转移，以​​达到圣杯，即手性诱导长度的度量；手性多物的创建；手性拓扑缺陷，诱发双轴性和天空；线路缺陷的多种“重新布线”；手性自组装单层用于纳米光子和半导体；以及高度复杂的油性和肥皂条纹液晶缺陷。 PI的团队采用了一系列实验工具，包括光学显微镜，共聚焦荧光显微镜，光学纳米摄影，原子力显微镜，AFM纳米光刻和椭圆法。 大部分工作都是与化学家戴维·阿夫尼尔（David Avnir）教授及其同事在耶路撒冷希伯来大学合作进行的。 By exploiting the PI's ability to create exquisitely tailored nano-scale chiral and topological defect easy axis patterns, and to image liquid crystal orientation down to x,y,z dimensions of 50 x 50 x 2 nm, this work is transforming our conceptions about - and methodology toward - chirality, defects, how the two can be coupled in anisotropic fluids, and broader issues in condensed matter. 特别是，PI的工作导致对诱发手性的理解，定量和剥削，以及对手性和精神拓扑缺陷的更深入了解，其操纵以及在光学和电子产品中的潜在应用。 随着手性和缺陷的后果出现在整个生物学，化学，物理学，医学，药理学和材料科学的过程中，研究的问题都涉及。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来评估通过评估来支持的。

项目成果

Magnetic field-induced Freedericksz transition in a chiral liquid crystal

手性液晶中磁场诱导的 Freedericksz 跃迁

• DOI: 10.1063/5.0146506
• 发表时间: 2023
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Missaoui, Amine;Susser, Adam L.;Aharoni, Hillel;Rosenblatt, Charles
• 通讯作者: Rosenblatt, Charles

Manipulation of mechanically nanopatterned line defect assemblies in plane-parallel nematic liquid crystals

• DOI: 10.1080/21680396.2022.2042745
• 发表时间: 2022-02-26
• 期刊: LIQUID CRYSTALS REVIEWS
• 影响因子: 5.1
• 作者: Harkai, Sasa;Cordoyiannis, George;Kralj, Samo
• 通讯作者: Kralj, Samo

Spontaneous Anchoring-Mediated Topography of an Orientable Fluid

• DOI: 10.1103/physrevlett.126.057803
• 发表时间: 2021-02-04
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Ferris, Andrew J.;Rosenblatt, Charles;Atherton, Timothy J.
• 通讯作者: Atherton, Timothy J.

Transition from escaped to decomposed nematic defects, and vice versa

• DOI: 10.1039/d0sm00218f
• 发表时间: 2020-05-28
• 期刊: SOFT MATTER
• 影响因子: 3.4
• 作者: Susser，Adam L.;Harkai，Sasa;Rosenblatt，Charles
• 通讯作者: Rosenblatt，Charles

Electric field driven reconfigurable multistable topological defect patterns

• DOI: 10.1103/physrevresearch.2.013176
• 发表时间: 2020-02-20
• 期刊: PHYSICAL REVIEW RESEARCH
• 影响因子: 4.2
• 作者: Harkai, Sasa;Murray, Bryce S.;Kralj, Samo
• 通讯作者: Kralj, Samo