Scalable Nanomanufacturing of Reconfigurable Photonic Crystals

晶体管的发明和大规模集成引发的微电子革命几乎影响了我们日常生活的方方面面。随着已有50年历史的摩尔定律接近极限，科学家们现在将目光转向光作为信息载体。不幸的是，与我们控制电子的能力相比，我们在纳米尺度上控制光的能力在很多方面还处于起步阶段。一种被称为光子晶体的新型光学材料可能是全光集成电路继续发展的关键。然而，传统的纳米制造技术生产具有三维有序纳米结构的光子晶体，存在着低通量、小样品面积和高成本的问题。通过将一种简单、快速、廉价的胶体自组装方法与一种新型形状记忆聚合物相结合，该项目将探索一种新的可扩展纳米制造方法，用于生产具有可重构光学特性的光子晶体。这项跨学科研究将通过大学的一些成功项目，与课程开发、新的示范模块设计以及对代表性不足的高中生和本科生的培训紧密结合。虽然各种胶体自组装技术已经开发出来，但大多数自下而上的方法只适合小批量、实验室规模的光子晶体生产。此外，具有固定微结构的自组装光子晶体仅适用于制造无源纳米光学器件。智能形状记忆聚合物可以从结构稳定的临时状态中记忆和恢复其永久形状，是开发有源光子晶体器件的理想材料。不幸的是，大多数现有的形状记忆聚合物都是热响应的，它们受到热要求的形状记忆循环的影响。该研究团队旨在进行同步的实验和理论研究，以解决当前胶体自组装和形状记忆聚合物技术面临的关键科学和工程障碍。现场纳米级机械和机械变色测试，以及多物理场机械有限元分析模拟，将有助于对新型形状记忆聚合物不同寻常的形状恢复机制的基本理解，从而实现非常规的全室温形状记忆循环。本文将通过光学表征和有限元光学模拟来阐明自组装光子晶体的微观结构与光学特性之间的耦合关系。采用可扩展的自底向上纳米制造技术，将制备出具有最佳晶体结构和多种可记忆光态的大面积大孔聚合物光子晶体。

The microelectronics revolution sparked by the invention and the very-large-scale integration of transistors has affected almost every aspect of our daily lives. As the 50-year-old Moore's law is approaching its limits, scientists are now turning to light as the information carrier. Unfortunately, our ability to control light in nanoscopic volumes is in many ways in its infancy, compared with how we can manipulate electrons. A new class of optical materials known as photonic crystals may hold the key to continued progress towards all-optical integrated circuits. However, traditional nanomanufacturing technologies for producing photonic crystals with three-dimensionally ordered nanostructures suffer from low throughput, small sample areas, and high cost. By integrating a simple, fast, and inexpensive colloidal self-assembly methodology with a new type of shape memory polymer, this project will explore a novel scalable nanomanufacturing approach for wafer-scale production of photonic crystals with reconfigurable optical properties. This interdisciplinary research will be closely integrated into curriculum development, new demonstration module design, and training of underrepresented high school and undergraduate students through a few successful programs at the university. Although various colloidal self-assembly technologies have been developed, most of these bottom-up approaches are only favorable for low volume, laboratory-scale production of photonic crystals. Moreover, self-assembled photonic crystals with fixed microstructures are only appropriate for fabricating passive nanooptical devices. Smart shape memory polymers that can memorize and recover their permanent shapes from structurally stable temporary sates are promising for developing active photonic crystal devices. Unfortunately, most of the existing shape memory polymers are thermoresponsive, and they suffer from heat-demanding shape memory cycles. The research team aims to conduct simultaneous experimental and theoretical investigations to address the key scientific and engineering barriers faced by the current colloidal self-assembly and shape memory polymer technologies. In-situ nanoscopic mechanical and mechanochromic tests, along with multiphysics mechanical finite element analysis simulations will facilitate the basic understanding of the unusual shape recovery mechanisms of the new type of shape memory polymer that enables unconventional all-room-temperature shape memory cycles. The stimuli-responsive microstructure-optical property relationship of the self-assembled photonic crystals will be elucidated by optical characterization and finite element optical simulations. Large-area macroporous polymer photonic crystals with optimal crystal structures and multiple memorizable optical states will be fabricated by the scalable bottom-up nanomanufacturing technology.