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.

该奖项资助应用原子尺度模拟研究纳米尺度摩擦物理学的新技术的开发。这些技术旨在延长模拟可实现的时间尺度，目前该时间尺度仅限于不到一微秒。 这使得当前的方法不适合模拟滑动速率远慢于 0.1 m/s 时发生的过程。 为了进行比较，AFM 实验和 MEM 滑动发生在 10-6 ? 10-9 m/s。 这些模拟方法也将扩展到本质上非平衡模拟。 预计这种长时间的非平衡模拟将有助于测试摩擦理论和模拟，其中实际模拟了单粗糙体接触。该项目的目标是扩展我们关于纳米尺度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) 的表面表征结果以及开发精密应用中的有效润滑方法至关重要。研究将能够分析摩擦响应相对于滑动速率和温度的转变。这些方法还将为研究碳氢化合物等吸附物的影响以及表面化学对摩擦和磨损的影响奠定基础，并有可能扩展到各种其他系统，包括断裂、疲劳、粘附和其他非平衡材料过程的研究。 该项目将支持一名研究生和博士后研究员。 研究员还将配合 JHU MRSEC 和 PREM 资助活动的外展活动，每年夏天将一名代表性不足的少数族裔学生带入实验室，以获得与 PI 和研究生密切合作的研究经验。