物理化学学报 >> 2013, Vol. 29 >> Issue (09): 1931-1936.doi: 10.3866/PKU.WHXB201305311

理论与计算化学 上一篇    下一篇

纳米器件的分子动力学模拟

孙玮, 张晋江, 赵健伟   

  1. 南京大学化学化工学院, 生命分析国家重点实验室, 南京 210008
  • 收稿日期:2013-03-29 修回日期:2013-05-30 发布日期:2013-08-28
  • 通讯作者: 赵健伟 E-mail:Zhaojw@nju.edu.cn
  • 基金资助:

    国家自然科学基金(21273113, 51071084)和国家科技支撑计划项目(2012BAF03B05)资助

Molecular Dynamics Simulation of a Nanosized Device

SUN Wei, ZHANG Jin-Jiang, ZHAO Jian-Wei   

  1. State Key Laboratory of Analytical Chemistry for Life, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008, P. R. China
  • Received:2013-03-29 Revised:2013-05-30 Published:2013-08-28
  • Contact: ZHAO Jian-Wei E-mail:Zhaojw@nju.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21273113, 51071084) and National Key Technology R&D Program of China (2012BAF03B05).

摘要:

分子动力学广泛应用于分子体系, 但受限于计算能力, 一般难以用于纳米器件的研究. 本文采用自主开发的超大规模分子动力学仿真程序(NanoMD), 构建了原子级的纳米齿轮模型, 并以此为代表实现了对具有高速转动特性的纳米器件的模拟. 通过位错和缺陷分析, 确定了纳米器件在高速转动过程中的应力分布以及失效机制, 并明确了以极限弹性转速为依据的材料强度衡量模式. 研究发现纳米器件在极限转速方面存在明显的尺寸效应: 随着器件直径的减小而单调增大, 随着轴径的缩小而先增大后减小.

关键词: 纳米器件, 纳米齿轮, 分子动力学模拟, 极限转速, 尺寸效应

Abstract:

Molecular dynamics (MD) simulations have been widely used for molecular systems; however, it is difficult to simulate nanosized devices because of limited computational capacity. Recently, we developed ultra-large MD simulation software, NanoMD. Here, we use this software to investigate a high speed rotatable nanodevice via the atomistic model of a nanogear. The stress distribution and failure mechanism of the nanodevice under high speed rotation is confirmed through dislocation defect analysis. The device strength is measured by focusing on the ultimate elastic rotation speed. There is an obvious size effect that limits the rotation speed of the nanodevice. The limiting speed increases with decreasing the diameter of the nanodevice. With shrinking the shaft diameter, it increases firstly, followed by a decrease.

Key words: Nano-device, Nano-gear, Molecular dynamics simulation, Limiting rotation speed, Size effect

MSC2000: 

  • O641