Photo-Aligning Molecular Orientations in Liquid Crystal Polymers into Complex Patterns for Programmable Origami

受日本折纸艺术的启发，编程折纸正在成为一种通过自主折叠二维材料来制造三维物体的新途径。要实现程序化折纸，小尺度的可编程折叠机构是关键，因此要求很高。液晶聚合物是与棒状或盘状分子单元结合的弱交联聚合物。当这些分子单元以不均匀的方向图案排列时，液晶聚合物可以被诸如温度和光的外部刺激触发而自变形。该奖项支持基础研究，以开发所需的技术，用于在小长度范围内以复杂模式对齐分子取向，并获得对如何设计分子取向模式以实现所需三维微结构的基本理解。三维微结构在诸如传感器、致动器、药物递送和光子器件的各种工业应用中是高度期望的。这项研究的成果应该有助于美国经济和造福社会。这一多学科的研究提供了一个很好的机会，教育研究生和本科生的知识和技能，在光子学，液晶科学和技术，纳米制造和数值模拟，并通过涉及少数民族和高中学生增强多样性。程序折纸承诺制造异国情调的三维微观和纳米结构的二维材料或结构的自折叠。该项目旨在开发在液晶聚合物膜的分子取向领域中压印折叠轨迹的能力。它将研究一种新的光图案化技术来定义复杂的分子取向顺序。它将发展分子取向和自我折叠过程之间的关系的基本理解。该研究团队将（1）设计、模拟、制造和表征等离子体光掩模，以获得所需的分子取向图案;（2）开发用于曝光光配向材料的光学曝光系统;（3）设计、建模和制造具有嵌入式分子取向顺序的液晶聚合物膜或微结构，并表征其在外部刺激下的形状演变。所提出的微图案化技术在几个方面具有优势：大规模图案化的能力，单次曝光和按比例放大的可行性。这项研究将产生基本的理解和新技术，以产生自折叠和扭曲的微结构和可编程的三维微/纳米制造。

As inspired by the Japanese art of paper folding, programmed origami is emerging as a new avenue towards manufacturing three-dimensional objects via autonomous folding of two-dimensional sheets of materials. To realize the programmed origami, a programmable folding mechanism at the small length scales is the key and thus in high demand. Liquid crystal polymers are weakly cross-linked polymers incorporated with rod or disk-like molecular units. When these molecular units are aligned in non-uniform directional patterns, the liquid crystal polymers can be triggered to self-deform by external stimuli such as temperature and light. This award supports fundamental research to develop the needed technology for aligning the molecular orientations in complex patterns in small length scales and to gain basic understanding on how to design molecular orientation patterns to achieve desired three-dimensional microstructures. Three-dimensional microstructures are highly desired in a variety of industrial applications such as sensors, actuators, drug delivery and photonic devices. The outcome from this research should contribute to the U.S. economy and benefit society. This multidisciplinary research provides a great opportunity to educate graduate and undergraduate students with knowledge and skills in photonics, liquid crystal science and technology, nanomanufacturing and numerical modeling, and to enhance diversity by involving minority and high-school students.Programmed origami promises manufacturing of exotic three-dimensional micro and nanostructures by self-folding of two-dimensional materials or structures. This project aims to develop capabilities to imprint folding trajectories of liquid crystal polymer films in their molecular orientation fields. It will study a novel photo-patterning technique for defining complex molecular orientation order. It will develop a basic understanding of the relationship between molecular orientation and self-folding processes. The research team will (1) design, simulate, fabricate and characterize plasmonic photomasks for desired molecular orientation patterns; (2) develop an optical exposure system for exposing photoalignment materials; and (3) design, model and fabricate liquid crystal polymer films or microstructures with embedded molecular orientational orders and characterize their shape evolution under external stimuli. The proposed photopatterning technique is advantageous in several aspects: capability of large scale patterning, single exposure and scaling-up feasibility. This research will yield both fundamental understanding and new technologies to produce self-folding and twisting microstructures and programmable three-dimensional micro/nanomanufacturing.