Template-based Fabrication of Three-dimensional, Chiral Plasmonic Nanostructures

手性描述的是物体在结构上的手性，这些物体与它们自己的镜像是不同的。手性在自然界中无处不在，最广为人知的是观察我们的左手和右手。手性也存在于许多糖分子、氨基酸和较大的蛋白质、核酸和病毒中，这些分子的手性对其功能有深远的影响；例如，手性分子在化学反应和与偏振光的相互作用中表现不同。受天然手性分子的启发，人工手性等离子体纳米结构正在探索利用它们的强光相互作用，实现“巨大”的光学响应，用于生物传感、光发射和光操纵等应用。手性等离子体纳米结构的实现要求等离子体材料被塑造成复杂的、亚波长的三维结构。然而，在所需的大面积上制造高密度的这些纳米结构并非易事。该奖项将结合自上而下的制造和自下而上的组装，以实现具有强偏振依赖光学特性的手性等离子体纳米结构。通过利用体材料和纳米晶体材料的不同物理特性，可以创造出对光和磁刺激有反应的手性材料。该团队将利用这些制造技术的简单性来设计一个新的光学设备制造实验室，使K-12和本科生参加科学节、营地和正式课程。该团队还将分享职业经验，鼓励女性从事科学和工程方面的职业。光学超材料通过设计物质的大小、形状和物理特性，以纳米级精度人工构建等离子体和非等离子体构建块，从而实现前所未有的光控制。其中，手性等离子体超材料结合了强光物质相互作用和其结构手性产生的独特极化选择性。该奖项旨在通过利用纳米压印光刻技术定义的尺寸和形状工程模板，以及块体和纳米晶体薄膜的不同沉积工艺和性能，推进大面积、多功能、三维、手性等离子体纳米结构的纳米级制造。通过将大块金属薄膜的角度选择性、阴影蒸发与胶体纳米晶体薄膜的各向同性沉积相结合，将产生层叠的、手性的纳米结构。利用块体和纳米晶体薄膜不同的化学和结构特性，应力将被用来驱动块体金属/纳米晶体纳米结构的屈曲，从而将平面二维纳米结构转变为三维手性纳米结构。通过整合不同的块体材料和纳米晶体材料，可以实现强极化依赖性和光磁响应性的手性材料。

Chirality describes the structural handedness of objects which are distinct from their own mirror images. Chirality is ubiquitous in nature and best known in looking at our own left and right hands. It is also found in many sugar molecules, amino acids and in larger proteins, nucleic acids and viruses, where chirality has a profound effect on function; for example chiral molecules behave differently in chemical reactions and in their interaction with polarized light. Inspired by natural chiral molecules, artificial chiral plasmonic nanostructures are explored to exploit their strong light interaction and realize 'giant' optical responses for applications including biosensing, light emission, and light manipulation. The realization of chiral plasmonic nanostructures requires plasmonic materials to be shaped into complex, subwavelength, three-dimensional architectures. However, it is not trivial to fabricate high densities of these nanostructures over the large areas required. This award will unite top-down fabrication and bottom-up assembly to realize chiral plasmonic nanostructures that have strong, polarization-dependent optical properties. By exploiting the disparate physical properties of bulk and nanocrystalline materials, chiral materials that are responsive to optical and magnetic stimuli will be created. The team will utilize the simplicity of these fabrication technologies to design a new optical device fabrication lab to make the field accessible to K-12 and undergraduate students participating in science festivals, camps, and formal curricula. The team will also share career experiences to encourage women to pursue careers in science and engineering. Optical metamaterials enable unprecedented control of light by engineering the size, shape, and physical properties of matter, artificially structured from plasmonic and non-plasmonic building-blocks with nanometer scale precision. Among them, chiral plasmonic metamaterials combine strong light-matter interactions with the unique polarization selectivity created by their structural handedness. This award aims to advance the nanoscale manufacturing of large-area, multi-functional, three-dimensional, chiral plasmonic nanostructures by exploiting size- and shape-engineered templates defined by nanoimprint lithography and the different deposition processes and properties of bulk and nanocrystal thin films. By combining angle-selective, shadow evaporation of bulk metal thin films with the isotropic deposition of colloidal nanocrystal thin films, hierarchal, chiral nanostructures will be created. Taking advantage of the distinct chemical and structural properties of bulk and nanocrystal thin films, stress will be exploited to drive buckling of bulk metal/nanocrystal nanostructures and thereby turn planar two-dimensional into three-dimensional, chiral nanostructures. By integrating different bulk and nanocrystal materials, strong polarization-dependent and optically and magnetically responsive chiral materials will be realized.