Extended Time Scale Simulation Studies of Nanoscale Friction

纳米级摩擦的延长时间尺度模拟研究

• 批准号: 0926111
• 负责人: Michael Falk
• 金额: $ 28万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926111&HistoricalAwards=false
• 关键词: Extended; Time; Scale; Simulation; Studies

This award funds the development of new techniques for applying atomic scale simulation to study the physics of nanoscale friction. These techniques aim to extend the time scales accessible with simulation, which are currently limited to less than a microsecond. This renders current methods unsuitable for simulating processes that take place at sliding rates considerably slower than 0.1 m/s. For comparison, AFM experiments and MEMs sliding take place at sliding speeds of 10-6 ? 10-9 m/s. These simulation methods will also be extended to inherently non-equilibrium simulations. It is anticipated that such long-time non-equilibrium simulations will be useful for testing theories of friction against simulations in which a single-asperity contact is realistically modeled.The goal of this project is to expand our knowledge regarding the fundamental physics and chemistry of friction on the nanoscale. Such knowledge is critical for the design of micro- and nano- electromechanical devices (MEMS/NEMS), interpreting the results of atomic force microscopy (AFM) for surface characterization and developing effective methods for lubrication in precision applications. Investigations will enable the analysis of transitions in frictional response with respect to sliding rate and temperature. These methods will also lay the groundwork for investigations into the effect of adsorbates such as hydrocarbons and the influence of surface chemistry on friction and wear and have the potential to be extended to a variety of other systems including studies of fracture, fatigue, adhesion and other non-equilibrium materials processes. The project will support a graduate student and postdoctoral researcher. The investigator will also coordinate with the outreach activities the JHU MRSEC and PREM grant activities to bring an underrepresented minority student into the lab each summer to gain research experience working closely with the PI and graduate student.

该奖项用于开发应用原子尺度模拟来研究纳米尺度摩擦物理的新技术。这些技术旨在延长可通过模拟获得的时间尺度，目前这些时间尺度被限制在不到一微秒。这使得现有的方法不适合于模拟滑动速度远低于0.1m/S的过程。作为比较，原子力显微镜实验和微机械滑动是在10-6、10-9m/S的速度下进行的。这些模拟方法还将扩展到固有的非平衡模拟。预计这种长期的非平衡模拟将有助于测试摩擦理论与模拟单个粗糙面接触的模拟。这个项目的目标是在纳米尺度上扩展我们关于摩擦的基本物理和化学的知识。这些知识对于微纳机电设备(MEMS/NEMS)的设计、解释原子力显微镜(AFM)表面表征的结果以及在精密应用中开发有效的润滑方法至关重要。研究将使分析摩擦响应相对于滑动速度和温度的转变成为可能。这些方法还将为研究碳氢化合物等吸附物质的作用和表面化学对摩擦和磨损的影响奠定基础，并有可能扩展到其他各种系统，包括断裂、疲劳、粘合和其他非平衡材料过程的研究。该项目将资助一名研究生和博士后研究员。调查员还将协调外展活动、JHU、MRSEC和PREM补助金活动，每年夏天将代表不足的少数族裔学生带到实验室，以获得与PI和研究生密切合作的研究经验。