COLLABORATIVE RESEARCH: DMREF: Designing Plasmonic Nanoparticle Assemblies For Active Nanoscale Temperature Control By Exploiting Near- And Far-Field Coupling

在DMREF项目和化学系的支持下，来自华盛顿大学的大卫J. Masiello教授、莱斯大学的Stephan Link教授和凯瑟琳A.来自坦普尔大学的Willets正在开发理论设计和实验实现一类新的周期性1D和2D热超材料的方法。热能或热量自然地从热流动到冷，使得即使在将热量施加到单个位置时也难以产生局部热“热点”。换句话说，供应的热功率与其引起的温度变化之间的空间相关程度可能很小。 触摸热锅的盖子提供了一个简单而又非常熟悉的例子。随着材料的尺寸减小到10- 100纳米，或者比人类头发的宽度小1,000倍，在一个小的空间区域内沉积和保持热能变得更具挑战性。然而，在纳米级（100 nm）和微米级（~1-100 μm）尺寸下控制热流和温度的能力对从大数据到纳米医学的应用具有重要意义。 该研究项目旨在克服热扩散，实现空间不均匀加热的远程全局控制，仅使用光来主动控制材料的热分布。除了影响各种各样的应用，该项目将促进学生和博士后研究人员的跨学科培训，通过三个研究小组之间的学生交流，组织两个新的科学会议，并设计了一个以光热材料为重点的中学生纳米技术夏令营。本项目的目标是通过理论设计和实验研究来克服热扩散，实现了一类新的周期性1D和2D热超材料。能够单独容纳空间可控纳米级热分布的等离子体纳米颗粒单元将被集成到周期性晶格中，这引入了在光学激发时对空间非均匀加热进行长距离全局控制的可能性。为了实现这一目标，研究团队将（i）扩展利用近场耦合的多粒子单位晶胞的设计和热表征能力;（ii）设计光子带结构，利用光在1D和2D Bravais晶格中塑造长程热分布;以及（iii）集成多个子晶格以实现1D和2D非布拉维晶格，从而使用光主动控制纳米尺度和微米尺度的热分布。这种热活性材料的实现将需要一个高技能团队的协调和迭代努力，该团队能够将新的理论方法与实验制造和表征技术相结合，预测光能如何转换为修改的热分布，以设计和量化数十年的长度尺度上的温度，从衍射极限以下到毫米。该项目将利用迭代的理论-实验-理论反馈回路来扩展主动可控光热材料的基因组。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the DMREF Program and the Division of Chemistry, Professor David J. Masiello from the University of Washington, Professor Stephan Link from Rice University, and Professor Katherine A. Willets from Temple University are developing methods to theoretically design and experimentally realize a new class of periodic 1D and 2D thermal metamaterials. Thermal energy, or heat, flows naturally from hot to cold, making it difficult to create localized thermal “hot spots” even when heat is applied to a single location. Said differently, the degree of spatial correlation between the heat power supplied and the temperature change that it induces is likely to be small. Touching a hot pan’s lid provides a simple and all too familiar example of this effect. As a material’s size is reduced to 10-100s of nanometers, or about 1,000 times smaller than the width of a human hair, depositing and maintaining thermal energy within a small region of space becomes even more challenging. Yet, the ability to control heat flow and thus temperature at both nanoscale (100 nm) and micron-scale (~1-100 μm) dimensions has important implications for applications ranging from big data to nanomedicine. This research project aims to overcome thermal diffusion and achieve long-range global control of spatially-nonuniform heating, using only light to actively control the thermal profile of the materials. Beyond impacting a wide variety of applications, the project will facilitate the interdisciplinary training of students and postdoctoral researchers through student exchange between the three research groups, organization of two new scientific meetings, and the design of a nanotechnology summer camp for middle school students with focus on photothermal materials.The goal of this project is to overcome thermal diffusion through the theoretical design and experimental realization of a new class of periodic 1D and 2D thermal metamaterials. Plasmonic nanoparticle unit cells that are individually capable of hosting spatially-controllable nanoscale thermal profiles will be integrated into periodic lattices, which introduces the possibility for long-range global control of spatially-nonuniform heating upon optical excitation. To achieve this goal, the research team will (i) expand the design and thermal characterization capabilities for multi-particle unit cells that exploit near-field coupling; (ii) engineer photonic band structure to sculpt long-range thermal profiles in 1D and 2D Bravais lattices using light; and (iii) integrate multiple sub-lattices to realize 1D and 2D non-Bravais lattices to actively control both nanoscale and micron-scale thermal profiles using light. Realization of such thermally-active materials will require the coordinated and iterative efforts of a highly-skilled team capable of integrating new theoretical methods for predicting how light energy is transduced into modified thermal profiles with experimental fabrication and characterization techniques to design and quantify temperature across decades of length scales, spanning from below the diffraction limit to millimeters. This project will leverage the iterative theory-experiment-theory feedback loop to expand the genome of actively-controllable photothermal materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.