NER: Directed and Selective Self-Assembly of Nanosized Particles via Surface-Plasmon Excitation

理解和实施主动的、定向的金属纳米颗粒组装对纳米技术的未来至关重要。纳米金属颗粒具有独特的光学和电学性质，这使它们成为在生物化学传感、通信、医学和电子领域应用的非常理想的构件。这项研究工作利用金属纳米结构独特的光学和热学性质，选择性地将其组装成活性纳米设备。这代表了迈向通用纳米组装技术的第一步，同时也探索了纳米级电磁学和热力学的基本问题。作为他们的主要目标，研究人员正在开发一种方法，使用原子力显微镜探针和表面等离子体激发，选择性地和局部地将纳米粒子融合成相干结构。金属纳米颗粒表面的熔化温度大大低于整体熔化温度，并允许利用光激发进行粒子融合。表面等离子激元共振的性质允许根据尺寸、材料和局部微观环境选择性地激发颗粒，从而为在同一时间框架内组装多种材料的集成工艺打开了大门。纳米粒子-纳米探针系统的研究将对理解纳米尺度的电磁学和热力学产生深远的影响。此外，新的纳米级组装技术的框架将使新的活性纳米设备成为可能，并使纳米组装技术得到更广泛的应用。该项目吸引了肯塔基斯大学的学生和研究人员参加两个纳米技术项目：纳米工程证书计划(NECP)和纳米技术保护伞计划(ON)。此外，参与这项研究的学生还接受电气、机械、生物系统和农业工程方面的研究人员的跨学科培训。

Understanding and implementation of active, directed assembly of metallic nanoparticles is crucial for the future of nanotechnology. Nanosized metallic particles have unique optical and electronic properties that make them highly desirable building blocks for applications in bio-chemical sensing, communications, medicine, and electronics. This research effort exploits the unique optical and thermal properties of metallic nanostructures to selectively direct their assembly into active nanodevices. This represents the first step toward a general-purpose nanoassembly technology while also exploring fundamental issues in nanoscale electromagnetics and thermodynamics. As their principle aim, the investigators are developing a method to selectively and locally fuse nanoscale particles into coherent structures using an atomic force microscopy probe and surface-plasmon excitation. The surfaces of metallic nanoparticles melt at temperatures dramatically lower than the bulk melting temperature and permit particle fusion using optical excitation. The nature of the surface plasmon resonances allows the particles to be selectively excited based on size, material, and local microscopic environment, opening the door for an integrated process that permits multiple materials to be assembled during the same time frame. The investigation of nanoparticle-nanoprobe systems will have a far reaching impact on the understanding of nanoscale electromagnetics and thermodynamics. In addition, a framework for a new nanoscale assembly technique will enable new active nanodevices and make nanoassembly technology more widely available. The project draws students and researchers from the University of Kentuckys two Nanotechnology Programs: the Nanoscale Engineering Certificate Program (NECP) and the Umbrella Program for Nanotechnology (UPoN). In addition, the students involved in this research effort receive interdisciplinary training with investigators in Electrical, Mechanical, and Biosystems and Agricultural Engineering.