Quartz Crystal Microbalance Studies of Atomic-Scale Friction

技术世纪后期标志着摩擦学基础领域的复兴，新的实验和理论技术能够研究在原子尺度上定义良好的几何形状中的摩擦力。该项目涉及使用这样一种技术，即石英晶体微量天平，以探讨这一领域的关键问题。 第一组实验将探索摩擦如何影响聚苯乙烯微球的定向运输，以记录通过原子尺度摩擦水平的变化来控制运动。第二个涉及研究滑动对单层厚氪层的二维熔点的影响，这对温升和热传输的基础研究很重要。 最后一组实验将记录磁场影响氦和氧薄膜的超导性依赖摩擦的牢固建立但仍知之甚少的现象的方式。我们的目标是加深我们的知识，电子贡献的能量耗散机制在滑动摩擦。一个免费的教育部分包括（1）本科生持续参与研究，（2）直接传播最先进的摩擦信息给制定该主题课程的教师，以及通过讲座和书面评论传播给更普通的受众。非技术性根据最新估计，提高对摩擦和磨损的关注将为发达国家节省高达1.6%的国民生产总值，仅美国每年就超过1000亿美元。随着能源价格的上涨，节约能源和原材料的需求变得越来越迫切，物理学家们对基本摩擦学过程的理解只能加速。世纪后期标志着摩擦学基础领域（摩擦和磨损研究）的复兴，这是由许多新的实验和理论技术引发的，这些技术能够在纳米尺度上明确定义的几何形状中研究摩擦力。该项目涉及使用一种这样的技术，即石英晶体微量天平（QCM），（1）探索摩擦对控制微米级颗粒的作用，这是包括医疗、电子和制造应用在内的新兴纳米技术领域的一个重要特征，（2）探测简化滑动接触的温度，这是一个非常难以从理论上量化的量，实验和计算的方法，（3）探索牢固建立，但仍然知之甚少的现象超导依赖摩擦。我们的目标是加深我们对电子如何导致能量损失的基本知识。一个免费的教育组成部分包括（1）本科生在研究中的持续参与，以及（2）直接传播最先进的摩擦信息的教师开发的主题课程，以及更一般的观众通过讲座和书面评论。

TechnicalThe late 20th century marked a renaissance in fundamental areas of tribology, sparked by new experimental and theoretical techniques capable of studying the force of friction in geometries which are well defined at the atomic scale. This project involves the use of one such technique, namely the Quartz Crystal Microbalance, to probe critical topics in this field. A first set of experiments will explore how friction impacts directed transport of polystyrene microspheres, to document control of motion through variations in atomic-scale friction levels. The second involves studies of the impact of sliding on the two-dimensional melting point of monolayer thick Krypton layers, important for fundamental studies of temperature rise and heat transport. The final set of experiments will document the manner in which magnetic fields influence the firmly established, yet still poorly understood phenomenon of superconductivity-dependent friction, for helium and oxygen films. The goal is to deepen our knowledge of electronic contributions to energy dissipation mechanisms in sliding friction. A complimentary educational component includes (1) ongoing participation of undergraduates in the research, and (2) direct dissemination of state-of-the-art information on friction to instructors developing curriculum on the topic, as well as to more general audiences through lectures and written reviews.Non-TechnicalBy most recent estimates, improved attention to friction and wear would save developed countries up to 1.6% of their gross national product, well over $100 billion annually in the U.S. alone. As the price of energy rises, and the need to conserve both energy and raw materials becomes increasingly urgent, physicists' rush to understand basic tribological processes can only be expected to accelerate. The late 20th century marked a renaissance in fundamental areas of tribology (the study of friction and wear), sparked by a number of new experimental and theoretical techniques capable of studying the force of friction in geometries which were are well-defined at the nanometer scale. This project involves the use of one such technique, namely the Quartz Crystal Microbalance (QCM), (1) to explore the role of friction to control micron scale particles, an important feature in emerging nano-technological areas that include medical, electronic and manufacturing applications, (2) to probe the temperature of a simplified sliding contact, a quantity that has been exceptionally difficult to quantify from theoretical, experimental and computational approaches, and (3) to explore the firmly established, yet still poorly understood phenomenon of superconductivity-dependent friction. The goal is to deepen our fundamental knowledge of how electrons contribute to energy loss. A complimentary educational component includes (1) ongoing participation of undergraduates in the research, and (2) direct dissemination of state-of-the-art information on friction to instructors developing curriculum on the topic, as well as to more general audiences through lectures and written reviews.