摘要
轻敲模式下探针从远离到间歇性接触样品表面,是一个连续的能量耗散过程.针对该连续过程的能量耗散机理研究仅零星存在于各个文献之中,对于连续过程中各个阶段的能量耗散机理也没有一个系统的解释和实验验证.本文提出了新的位移激励下原子力显微镜探针-样品系统简化模型并得到了一维振子系统等效阻尼的计算方法,并通过该方法计算了探针在远离样品表面时的空气黏性阻尼和靠近样品时的空气压膜阻尼,分析了探针从远离样品到间歇性接触样品表面这一过程中的环境耗散机理变化,得到了原子力显微镜系统理论品质因数与探针工作位置的关系曲线;在此基础上设计了轻敲模式下的微悬臂梁扫频实验,得到了系统实验品质因数与探针工作位置的关系曲线,进而验证了理论模型的准确性.本文通过对轻敲模式下AFM环境耗散机理进行理论分析和实验验证,希望可以对轻敲模式下AFM动力学特性及其阻尼作用机理有更近一步的认识,同时对微纳米机电系统(MEMS/NEMS)能量耗散机理的研究提供理论参考和实验方法.
In the tapping mode, the AFM probe experiences a continuous energy dissipation process when the probe gradually approaches the sample from a far distance to an intermittent contact. Researches on the energy dissipation mechanism of this continuous process still exists sporadically in various literatures, and there are few systematic explanations and experimental verifications for the energy dissipation mechanism of each stage in the continuous process. In this paper, a new simplified model of the AFM probe-sample system under displacement excitation is proposed, and a calculation method for the equivalent damping of the one-dimensional vibration system is obtained. By this method, the viscous damping of the air when the probe is far away from the sample surface and the air squeeze film damping when the probe is close to the sample are calculated. Finally, the change of the environmental dissipation mechanism in the process from the probe away from the sample to the intermittent contact with the sample surface is analyzed, and the relationship curve between the theoretical quality factors of the AFM system and the working positions of the probe is obtained. Based on this, the micro-cantilever frequency sweep experiments with different probes in tapping mode are carried out. The frequency sweep curves are obtained through the experiments, thus obtaining the experimental relationship curve between the quality factors of the system and the working positions of the probe. The accuracy of the theoretical model is verified from the experiments. Through theoretical analysis and experimental verification of the AFM environmental dissipation mechanism in tapping mode, a further understanding of the dynamics characteristics of tapping mode AFM and its damping mechanism will be provided by this study. At the same time, it provides theoretical reference and experimental methods for the research of the energy dissipation mechanism in Micro-nano electromechanical system(MEMS/NEMS).
作者
魏征
郑骁挺
刘晶
魏瑞华
Wei Zheng;Zheng Xiaoting;Liu Jing;Wei Ruihua(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing,100029,China)
出处
《力学学报》
EI
CSCD
北大核心
2020年第4期1106-1119,共14页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(11572031)。
关键词
原子力显微镜
动力学模型
能量耗散
空气阻尼
压膜阻尼
atomic force microscope
dynamics model
energy dissipation
air damping
squeeze damping
