Collaborative Research: Electric-field Directed Assembly of 3D Chiral Metamaterials

合作研究：3D 手性超材料的电场定向组装

• 批准号: 1611330
• 负责人: Ning Wu
• 金额: $ 27万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611330&HistoricalAwards=false
• 关键词: Collaborative; Research; Electric; field; Directed

Chirality is a fundamental characteristic of living matter. Chiral metamaterials are engineered structures composed of periodic metallodielectric building blocks that exhibit chirality. The resonance of individual building blocks and strong coupling between neighbors allow the realization of exotic electromagnetic properties such as negative refractive index and giant circular dichroism. Chiral metamaterials could revolutionize many modern technologies including superlenses, optical communication, cloaking devices, and high resolution sensors. Three-dimensional chiral metamaterials are, however, extremely difficult to fabricate especially in an economical and large scale fashion. This research will utilize asymmetric particles as building blocks and exploit a time-varying electric field to guide the assembly of these particles into long-range periodic chiral structures. The solution-based process could potentially reduce the fabrication cost significantly. The compatibility of the electrode design with existing microelectronic manufacturing infrastructures will also open the door to commercialize innovative metamaterials for emerging applications. The research team will also engage both high school and undergraduate students with immersive research experiences. Learning modules such as "Colloids, surfactants, and our daily lives" and "Optical technology that changes our lives" will be developed in collaboration with K-12 teachers. The research findings will also be included in the development of several multi-disciplinary courses such as "Engineering of Soft Materials" and "Nanotechnology: From Molecules to Machines". The goal of this collaborative project is to use electric fields to assemble Janus metallodielectric particles into a periodic array of chiral clusters as an efficient bottom-up route for making three-dimensional chiral metamaterials. Particles with increasing morphological complexity will be fabricated as building blocks by glancing angle deposition. A liquid electrode cell will be built for the manipulation of the Janus particles via time-varying electric fields in three-dimensions. The Coulomb, dipolar, and electrohydrodynamic interactions will be exploited to guide the assembly of Janus particles into chiral clusters. Further manipulation of the chirality of the electric fields will transform the racemic mixture into enantiomerically pure clusters. The photonic response of the fabricated structures and their applications will be measured and explored in both near-infrared and visible regions. Numerical simulations will also be performed to elucidate the particle assembly mechanisms, their optical properties, and guide experimental optimization. The collaborative and iterative nature of this project will reveal the interrelationship between the design of fundamental building blocks, control of lattice symmetry, and targeted photonic properties of chiral metamaterials.

手性是生命物质的基本特征。手性超材料是由具有手性的周期性金属介电材料组成的工程结构。单个构件的共振和相邻构件之间的强耦合允许实现奇异的电磁特性，如负折射率和巨大的圆二色性。手性超材料可以彻底改变许多现代技术，包括超透镜、光通信、隐形设备和高分辨率传感器。然而，三维手性超材料的制造是极其困难的，特别是在经济和大规模的方式。本研究将利用不对称粒子作为构建单元，并利用时变电场引导这些粒子组装成远程周期性手性结构。基于解决方案的工艺可能会显著降低制造成本。电极设计与现有微电子制造基础设施的兼容性也将为新兴应用的创新超材料商业化打开大门。该研究团队还将吸引高中生和本科生进行沉浸式研究体验。“胶体、表面活性剂和我们的日常生活”和“改变我们生活的光学技术”等学习模块将与K-12教师合作开发。研究成果亦会被纳入“软材料工程”及“纳米技术：从分子到机器”等多学科课程的发展中。这个合作项目的目标是利用电场将Janus金属介电粒子组装成一个周期性的手性簇阵列，作为一种有效的自下而上的方法来制造三维手性超材料。通过掠角沉积，可以制造出具有越来越复杂形态的粒子。将建立一个液体电极电池，通过时变电场在三维空间中操纵Janus粒子。库仑、偶极和电流体动力学相互作用将被用来指导Janus粒子组装成手性团簇。进一步操纵电场的手性将使外消旋混合物转变为对映体纯团簇。将在近红外和可见光区域测量和探索所制备结构的光子响应及其应用。数值模拟也将用于阐明粒子的组装机制、光学性质和指导实验优化。这个项目的协作和迭代性质将揭示基本构建块的设计、晶格对称性的控制和手性超材料的目标光子特性之间的相互关系。