Nanometer Scale Surface-Mounted Molecular Dipolar Rotors and Rotor Arrays

该功能纳米技术奖授予了科罗拉多大学博尔德分校的Josef Michl和John Price教授以及西北大学的Mark Ratner教授，该奖项由化学先进材料和加工项目、土木和机械系统分部的表面工程和摩擦学项目、国际项目司的西欧项目以及数学和物理科学理事会的多学科活动办公室。研究了纳米级表面安装分子偶极转子和转子阵列的设计、合成和表征。基本装置将是一个表面安装的分子偶极子转子，其底座共价附着在平坦的绝缘表面上，并支撑垂直安装在表面上的轴，轴又支撑一个平衡的1-2 nm直径的转子，具有较大的面内电偶极矩。轴承是分子尺度力学的基本元素，将由金属-面键组成。将构建单转子和相互作用转子的自组装阵列。通过适当的化学结构设计，可以控制转子的尺寸和转动惯量、离表面高度、转动摩擦、偶极子的大小、偶极子阵列的间距及其居里温度、传播速度和耗散。转子阵列有许多潜在的应用，如铁电、压电和热释电材料，并将有助于减少电压可调滤波器、振荡器、移相器以及传感器、致动器、延迟线和谐振器的尺寸。这些进步最终将有助于射频产品的小型化，如蜂窝手机和无线调制解调器。参与研究人员在综合、表征和理论方面的协同互动将为参与研究的学生提供宝贵的跨学科学习经验。

This Functional Nanotechnology award to Professors Josef Michl and John Price at the University of Colorado-Boulder and Professor Mark Ratner at Northwestern University is supported by the Advanced Materials and Processing Program in Chemistry, the Surface Engineering and Tribology Program in the Division of Civil and Mechanical Systems, the Western Europe Program in the Division of International Programs and the Office of Multidisciplinary Activities in the Mathematical and Physical Sciences Directorate. The research deals with the design, synthesis and characterization of nanometer scale surface-mounted molecular dipolar rotors and rotor arrays. The basic device will be a surface-mounted molecular dipolar rotor, whose base attaches covalently to a flat insulating surface and supports an axis mounted perpendicularly to the surface, which in turn supports a balanced 1-2 nm diameter rotor with a large in-plane electric dipole moment. The bearing, a fundamental element of molecular-scale mechanics will consist of a metal-to-pi-face bond. Both single rotors and self-assembling arrays of interacting rotors will be constructed. The size and moment of inertia of the rotor, its height above the surface, the rotational friction, the magnitude of the dipole, the spacing of the dipole array and its Curie temperature, propagation velocities and dissipation will be controlled by appropriate design of chemical structures. Rotor arrays have many potential applications as ferroelectric, piezoelectric and pyroelectric materials, and will be useful in reducing the size of voltage-tunable filters, oscillators, phase-shifters as well as sensors, actuators, delay lines and resonators. Such advances would ultimately contribute to miniaturization of RF products such as cellular handsets and wireless modems. Synergistic interactions between the participating investigators in synthesis, characterization and theory will provide a valuable, interdisciplinary learning experience for the students involved.