利用热机械噪声研究单壁碳纳米管的动态黏附力学特性及机理

Adhesion interaction is a main reason that causing failure of nanotube (CNT)-based Micro/Nano-electromechanical system (MEMS/NEMS) and sensors, thoroughly understanding of mechanism of energy dissipation in adhesion process gives rise a way in improving the yield rate for NEMS devices. However, the current mechanical peeling methods that is commonly used to study adhesion properties of single wall carbon nanotube (SWNT) encounter obstacles when it comes to higher frequency domain. Thermal mechanical noise is an intrinsic noise that widely exist in a wide frequency range in Micro/Nano scale devices. Based on high resolution measurement of thermal mechanical noise of cantilever in a wide frequency range, in the project, we are aiming to study adhesion mechanics and energy dissipation of SWNT, reveal adhesion response properties of SWNT in different time scales, and get insight into energy dissipation mechanism by varying parameters of amorphous carbon coating on SWNT...We expect that after this research project we will get a full understanding of adhesion and dissipation of SWNT in different time scales and a thorough reveal of physical mechanism for adhesion related lose in performance, provide useful suggestions in the design of novel CNT-based resonators and sensors with higher resolution and stability.

黏附失效是导致基于碳纳米管的微纳机电器件及传感器失效的主要形式，探明黏附作用引起的力学特性和能量耗散机制以实现对黏附过程有效控制是进一步提高器件性能和良品率的重要步骤。常规的机械剥离方法对研究碳纳米管高频振动黏附特性存在局限性。热机械噪声是小尺度器件中频域宽广的固有噪声，本项目拟以微悬臂梁连续频率热机械噪声的测量和分析为切入点：(1) 研究单壁碳纳米管动态黏附力学和能量耗散特性, 探明单壁碳纳米管黏附响应的时间尺度特性；(2) 通过对碳纳米管黏附剥离过程同步施加动态激励，研究单壁碳纳米管的黏附刚度和能量耗散沿碳纳米管剥离方向的空间分布规律；(3) 利用高能电子束选择性激发碳纳米管，研究单壁碳纳米管管壁无定形碳质层对能量耗散的贡献机理和特性。本项目的开展将揭示碳纳米管黏附过程中的动态力学和能量耗散属性，为探寻黏附失效物理机制、设计发展高性能微纳机电系统等提供科学参考依据。