纳米阵列结构失稳机理的研究

项目名称： 纳米阵列结构失稳机理的研究

项目编号： No.11502197

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 杨帆

作者单位： 西安科技大学

项目金额： 22万元

中文摘要： 纳米梁阵列由纳米梁按一定方式排列与组装构成，它是下一代纳米结构器件设计的材料基础，在亚微米器件中有着潜在的应用前景。无论对于它的制造还是使用，稳定性都是一个重要环节。然而，其失稳机制尚未明确，振动响应方面的研究有待进一步深入。纳米阵列内部的纳米梁尺度达到纳米级，呈现出极大的表面积，形成表面效应。同时，伴随结构内部单根纳米梁之间距离减小，仅为几十纳米。分子间作用力凸显，与表面效应一起成为影响纳米阵列力学行为的重要影响因素。本项目拟采用理论分析、有限元与分子模拟相结合的方法研究纳米阵列的静态与动态失稳机制，计及表面效应与分子间作用力，建立纳米阵列弹性变形及振动频率、振幅等与结构尺寸、边界条件和外加载荷的定量关系，探明结构的静态与动态失稳机制。本项目的开展将能用于纳米阵列的力学性能测试和评估，对纳米阵列的设计和使用提供理论安全数据和指导。

中文关键词： 纳米阵列；失稳机理；振动响应；表面效应；分子间作用力

英文摘要： Nano-forest are the fundamental building blocks of nano devices and widely used as laser technique and data storage in nano-electromechanical system (NEMS). Nano-forest are composed of nano-beams in a certain way. For manufacture and using of nano-forest, the analysis of instability mechanism is an important part. For typical nano- forest in nano-electro-mechanical systems, there are only dozens of nanometers in thickness and the initial separation of the beams in the forest. When the initial separation decreases to sub-micrometers, the intermolecular effects such as Casimir force and van der Waals force play a dominate role in the instability mechanism of nano- forest. The van der Waals force is known to be dominant when the initial separation is less than 20 nm, while the Casimir force is known to be more profound when the initial separation is more than 20 nm. And due to the inherently large surface area to volume ratio, surface effects are expected to contribute significantly to the mechanical response of nano-beams, which are the main components of the nano-forest. Both the surface effects and intermolecular forces play an important role in the mechanical performance of nano-forest. In this project, theoretical analysis, finite element analysis and molecular simulation are performed to investigate the instability and vibration of nano-forest with both surface effects and intermolecular forces. Based on the surface elasticity, we analyze elastic response of nano-forest under loading. It is expected to found the dependence of the deformation as well as the vibration frequency, amplitude on the nano-forest extrinsic geometry, boundary conditions and loading mode. These works are helpful to measure and evaluate the mechanical properties of nano-forest and importance to manufacture and using of reliable and durable nano-forest.

英文关键词： nano-forest;instability mechanism;vibration response;surface effects;intermolecular effects