Programmable and Emergent Structures in Soft Matter: Chirality, Polarity, and Auto-Origami

软物质中的可编程和紧急结构：手性、极性和自动折纸

• 批准号: 1409658
• 负责人: Robin Selinger
• 金额: $ 37.5万
• 依托单位: Kent State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1409658&HistoricalAwards=false
• 关键词: Programmable; Emergent; Structures; Soft; Matter

Non-technical Summary:This award provides support for theoretical studies of responsive liquid crystal polymers, a form of plastic that spontaneously changes shape under heating or cooling. Rod-shaped liquid crystal molecules bonded to the polymer's main chains are disordered in orientation at high temperature but align at low temperature, inducing the polymer chains to extend in a parallel direction, and as a result the material stretches when cooled. Some materials containing light-sensitive dyes also change shape in response to illumination. A sample prepared with a non-uniform imposed pattern of local molecular orientation, a process known as blueprinting, shows complex shape evolution as the induced stress/strain is not uniform. The blueprinted pattern thus encodes a complex trajectory of movement from an initial state, e.g. a flat thin film, to a final state that is folded, curved, or twisted, a form of programmed auto-origami. Computer simulation studies of this process will explore the mathematical relationship between blueprinted structures and the resulting shape change. These materials have potential application in robotics, light-driven mechanical devices, touch displays, biomedical devices, and switchable surface textures. Related studies will examine shape change, pattern formation, and phase behavior in lipid membranes and liquid crystals. Outreach efforts, including research internships for 60+ high school students and annual science fair for six school districts, attract students to STEM careers and aim to improve the diversity of the STEM workforce.Technical Summary:This award supports theoretical/computational research and education in soft matter physics. It combines computer simulation and fundamental theory to investigate mechanisms of microstructural/shape evolution and pattern formation in soft matter. The proposed theory/modeling studies of orientationally ordered lipid membranes and nematic solids are united by themes of differential geometry, curvature, topological defects, complex ordering and response, topology, and self-assembly. The principal problems to be investigated are: (1) Auto-origami: nematic solids as programmable, stimuli-responsive materials; (2) Lipid membranes: coupling of topological defects and curvature; (3) Phase transitions in liquid-crystal elastomers: kinetic evolution of polydomain structures; (4) Flexoelectricity in liquid crystals: formation of complex modulated phases. In all of these cases, the PI's will collaborate with experimental scientists to compare predictions with experiments on physical and biological systems.This research is connected to fundamental problems in self-assembly, nonlinear elasticity, topological defects, and differential geometry. Potential applications of outcome of this research could include soft actuators, shape control of lipid vesicles for drug delivery, self-assembly of vesicles for photonic crystals, and new liquid-crystal display technologies and switchable surface textures.

非技术摘要：该奖项为响应式液晶聚合物的理论研究提供了支持，这种塑料形式自发地在加热或冷却下改变形状。在高温下粘合到聚合物主链上的杆状液晶分子在高温下的方向无序，但在低温下对齐，从而诱导聚合物链在平行方向上延伸，结果材料在冷却时伸展。一些含有光敏染料的材料也会因照明而改变形状。以非均匀施加的局部分子取向模式制备的样品（称为蓝图的过程）显示出复杂的形状进化，因为诱导的应力/应变并不均匀。因此，蓝图模式编码了从初始状态，例如一种扁平的薄膜，达到最终状态，折叠，弯曲或扭曲，是一种编程的自动孔。对此过程的计算机仿真研究将探讨蓝图结构与所得形状变化之间的数学关系。这些材料在机器人技术，轻驱动机械设备，触摸显示器，生物医学设备和可切换表面纹理中具有潜在的应用。相关研究将检查脂质膜和液晶的形状变化，模式形成和相行为。推广工作，包括针对60多名高中学生的研究实习和六个学区的年度科学博览会，吸引学生从事STEM职业并旨在改善STEM劳动力的多样性。技术摘要：该奖项支持软物质物理学的理论/计算研究和教育。它结合了计算机模拟和基本理论，以研究软物质中微观结构/形状演化和模式形成的机制。提出的对定向有序的脂质膜和列固体的理论/建模研究由差分几何，曲率，拓扑缺陷，复杂有序和反应，拓扑，拓扑和自组装的主题结合在一起。要调查的主要问题是：（1）自动式固体：可编程的刺激性响应材料； （2）脂质膜：拓扑缺陷和曲率的耦合； （3）液晶弹性体中的相变：多域结构的动力学演化； （4）液晶中的挠性电源：形成复杂的调制相。在所有这些情况下，PI的合作将与实验科学家合作，将预测与物理和生物系统的实验进行比较。这项研究与自组装，非线性弹性，拓扑缺陷和差异几何的基本问题有关。 这项研究结果的潜在应用可能包括软执行器，用于药物输送的脂质囊泡的形状控制，光子晶体的囊泡自组装以及新的液体结晶显示技术和可切换的表面纹理。