Thermally Responsive Surface Topologies from Patterned Reactive Mesogens

点击翻译按钮获取中文摘要

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.