Collaborative Research: CDI-Type II: First-Principles Based Control of Multi-Scale Meta-Material Assembly Processes

胶体纳米或微米粒子组装成完美有序的周期性结构为制备具有独特电、磁和光学性能的光子带隙材料和其他多尺度超材料提供了基础。尽管已经在实验室中制造了概念验证材料来验证其惊人的特性，但现有的工艺还没有足够的可控性、可扩展性和健壮性来实现高通量制造，从而实现商业应用。胶体组分组装成有序结构的基本限制是热运动、粒子间相互作用和导致缺陷丰富且经常停滞的外场的复杂相互作用。我们提出了一种新的方法来解决超材料组装问题，该方法结合了四个独立的科学领域的专业知识，这些领域传统上相互作用最少。胶体系统的数学模型将使用先进的显微成像和分析工具的数据来构建，这些模型在一些关键变量中表示为自由能景观(FEL)，这些变量表征了组装过程的状态。FEL反过来将被用作为随机过程开发的严格过程控制算法的输入，这些算法将在环境中导航，以产生无缺陷的产品。这一战略将在实验室规模的原型反应堆上进行演示和改进，使用实时数字显微成像作为传感器，以可编程的粒子-粒子相互作用势和电场作为致动器来生产超材料。就更广泛的影响而言，成功开发用于大规模组装无缺陷胶体晶体的基本工具，有可能产生革命性的技术(如光学计算、能量采集、亚衍射极限成像、隐形隐身)，就像创造单晶硅以实现集成电路和现代计算一样。尽管经过了25年的反复试验，但目前还没有一种现有的工艺能够在商业规模上生产这种材料。需要一种使用定量准确的过程模型的严格实时控制策略，就像这里提出的那样。教育和外展活动将结合建模、控制、模拟和实验的综合概念，包括来自胶体实验(例如图像、视频)和基于物理的模拟(例如渲染、动画)的丰富视觉数据，为各级学生提供直观的教育/培训。

The assembly of colloidal nano- or micro-particles into perfectly ordered periodic structures provides a basis for manufacturing photonic band gap materials and other multi-scale meta-materials with unique electric, magnetic, and optical properties. Although proof-of-concept materials have been made in laboratories to verify their amazing properties, no existing process is yet sufficiently controllable, scalable, and robust for high-throughput manufacturing to enable commercial applications. The fundamental limitation to assembling colloidal components into ordered structures is the complex interplay of thermal motion, interparticle interactions, and external fields that lead to defect-rich and often arrested states. We propose a new approach to the meta-material assembly problem that combines expertise from four separate scientific fields that traditionally have had minimal interaction. Mathematical models of the colloidal systems, represented as free energy landscapes (FELs) in a few key variables that characterize the state of the assembly process, will be constructed using data from advanced microscopic imaging and analysis tools. The FELs will in turn be used as input to rigorous process control algorithms, developed for stochastic processes, that will navigate the landscapes to yield defect-free products. This strategy will be demonstrated and refined on prototype lab-scale reactors, using real-time digital microscopic imaging as the sensor and programmable particle-particle interaction potentials & electric fields as the actuators, to produce meta-materials.In terms of broader impact, successful development of fundamental tools for large-scale assembly of defect-free colloidal crystals has the potential to produce revolutionary technologies (e.g. optical computing, energy harvesting, sub-diffraction limit imaging, invisibility cloaking) not unlike the creation of single crystal silicon to enable integrated circuits and modern computing. No existing processes today are capable of producing such materials at a commercial scale despite 25 years of trial-and-error efforts. A strategy of rigorous real-time control using quantitatively accurate process models, like that proposed here, is required. The education and outreach activities will incorporate integrate concepts from modeling, control, simulations, and experiments, including rich visual data from colloid experiments (e.g. images, videos) and physics-based simulations (e.g. renderings, animations) to provide intuitive education/training for students at all levels.