Thermally Responsive Surface Topologies from Patterned Reactive Mesogens

这项工作的基础科学目标是通过先进的实验表征和建模，以创建热响应的微，介和纳米表面浮雕拓扑结构，并从根本上了解他们的可定制性通过界面，分子和热力学控制的图案化反应液晶薄膜的局部热膨胀“景观”的详细了解。 通过以周期性方式对被锁定的各向同性无序包围的捕获的螺旋双有序区域进行空间图案化，可以创建和热激活丰富多样的表面拓扑结构。 提出了三种制作方法来定制不同尺寸的表面浮雕特征，包括微米级的光刻，中尺度的全息光刻和纳米级的模板。 将进行一系列实验（光学、热光学、干涉、电子和共焦显微镜以及核磁共振）来探测它们的热、结构、光学和动态特性，以阐明它们的基本拓扑结构和潜在的物理现象，并评估它们的潜在用途在应用中。 研究生和本科生都将接受使用这些现代实验技术的培训。 与荷兰埃因霍温技术大学建立了国际合作，使学生可以利用他们在反应介晶化学方面的设施和专业知识，并体验国际合作的重要性。 在液晶科学的跨学科界面上，对反应性液晶（或介晶）的兴趣不断增加，为永久捕获各种液晶相和配置用于被动和主动光学应用提供了独特的机会，并进一步加深了对液晶有序的基本理解。 该提案的目标是创建一个图案化的聚合物样品，它对热量作出反应。 通过向样品施加热量，样品的区域将膨胀（弹出），并且相邻区域将保持水平。 这产生了在整个样品上具有高度差异的膜。 由于它被设计成周期性的，它可能对引导光的新光学设备有用。 通过了解这种新效应背后的基础科学，这种材料可以优化用于许多有趣的应用领域，包括电信交换机，平板显示器以及护照和货币的安全功能。 该提案产生的研究成果将被整合到本科和研究生创业课程中，学生们将努力从大学的发现和创新中创造商业和社会价值。 参与研究的研究生也将大大受益于荷兰埃因霍温技术大学的国际研究经验，在那里他们不仅将利用科学专业知识和最先进的基础设施，而且还将体验国外的研究企业。 这项提案的教育推广部分意义深远--这项工作的目标是激励和使大普罗维登斯地区的年轻人，特别是那些来自手段和资源有限的社区的年轻人，那些有教育问题和行为问题的年轻人，那些被监禁的年轻人，以及残疾人，充分发挥他们的生产潜力，以科学和工程学为载体的负责任和有爱心的公民。 将开发两个新的教育推广平台来实现这一雄心勃勃的目标，其中包括艺术/时尚和科学的交叉，以及基于基本科学主题和事实的新型卡通媒体。

The underpinning scientific goal of this work is to develop a detailed understanding of the local thermal expansion "landscape" of patterned reactive mesogen films through advanced experimental characterization and modeling to create thermally responsive micro-, meso-, and nano-surface relief topologies, and to fundamentally understand their tailorability through interfacial, molecular, and thermodynamic control. By spatially patterning regions of captured helical cholesteric order surrounded by locked-in isotropic disorder in a periodic way, a rich variety of surface topologies can be created and thermally activated. Three fabrication methodologies are proposed to tailor surface relief features on different dimensions, including lithography for the micrometer-scale, holo-lithography for the meso-scale, and templating for the nano-scale. A battery of experiments will be performed (optics, thermo-optics, interference, electron, and confocal microscopy, and nuclear magnetic resonance) to probe their thermal, structural, optical, and dynamic properties to elucidate their basic topology and underlying physical phenomena, and evaluate their potential use in applications. Both graduate students and undergraduate students will be trained to use these modern experimental techniques. An international collaboration with the Technical University of Eindhoven in the Netherlands has been established so students can capitalize on their facilities and expertise in reactive mesogen chemistry, as well as experience the importance of international collaboration. %%%An increasing interest in reactive liquid crystals (or mesogens) continues to emerge at the cross-disciplinary interface of liquid crystal science, offering unique opportunities to permanently capture various liquid crystalline phases and configurations for passive and active optical applications, and to further the fundamental understanding of liquid crystalline ordering. The goal of this proposal is to create a patterned polymer sample, which responds to heat. By applying heat to the sample, regions of the sample will expand (pop-up) and adjacent regions will remain level. This creates a film with differences in height across the sample. Since it is designed to be periodic, it may be useful for new optical devices that steer light. By understanding the basic science behind this novel effect, the material can potentially be optimized for use in a number of intriguing application areas, including telecommunications switches, flat panel displays, and security features for passports and currency. The research results emanating from this proposal will be integrated into undergraduate and graduate entrepreneurship courses where students strive to create commercial and societal value out of university discoveries and innovations. The graduate students participating in the research will also greatly benefit from the international research experience with the Technical University of Eindhoven in the Netherlands, where they will not only capitalize on scientific expertise and state of-the-art infrastructure, but they will also experience the research enterprise in a foreign country. The education outreach component of this proposal is far reaching - it is the goal of this work to inspire and enable young people in the Greater Providence Area, particularly those from neighborhoods of limited means and resources, those who have had educational troubles and behavioral problems, those who are incarcerated, and those with disabilities, to realize their full potential as productive, responsible and caring citizens using science and engineering as a vehicle. Two new educational outreach platforms will be developed to accomplish this ambitious goal, which includes the intersection of art/fashion and science, and a novel cartoon medium based on underlying scientific themes and facts.