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.

该奖项为应用原子量表模拟来研究纳米级摩擦的物理学提供了新技术的发展。这些技术旨在扩展可通过模拟访问的时间尺度，这些时间尺度目前仅限于微秒。 这使得当前方法不适合模拟以滑动速率慢于0.1 m/s的过程。 为了进行比较，在10-6的滑动速度下进行AFM实验和MEMS滑动？ 10-9 m/s。 这些模拟方法也将扩展到固有的非平衡模拟。 可以预料，如此长期的非平衡模拟将有助于测试摩擦理论，以实现单个弥漫性接触现实建模的模拟。该项目的目的是扩大我们对纳米级摩擦的基本物理和化学的知识。 这种知识对于设计微动力器械（MEMS/NEM）的设计至关重要，解释了原子力显微镜（AFM）的结果，用于表面表征和开发精确应用中润滑的有效方法。调查将使在滑动速率和温度方面的摩擦反应中的过渡分析。这些方法还将为研究吸附物（例如碳氢化合物）的影响以及表面化学对摩擦和磨损的影响奠定基础，并有可能扩展到其他各种系统，包括裂缝，疲劳，粘附和其他非平衡材料过程。 该项目将支持研究生和博士后研究员。 调查人员还将与JHU MRSEC和PRER GRANT活动协调，每年夏天将一名代表性不足的少数民族学生带入实验室，以获得与PI和研究生紧密合作的研究经验。