【作者】 房轩；

【导师】 胡小唐；

【作者基本信息】 天津大学 ， 测试计量技术及仪器， 2004， 硕士

【摘要】 自从原子力显微镜(AFM)诞生以来，其检测技术得到迅速发展，应用范围也日趋广泛。目前，原子力显微镜已成功的应用于物理、化学、金属、半导体、微电子、纳米材料、生物、生命科学等众多科学领域中。而且目前已经有人利用AFM的微悬臂梁做为传感器来检测生物化学反应，可以说AFM已经成为进行微观领域研究的重要工具。AFM微悬臂梁有三种工作方式：接触模式(Contact Mode)、非接触模式(Non-Contact Mode)和轻敲模式(Tapping Mode)，由于轻敲模式对样品的损坏较小，因此在生物化学检测方面具有特别的优势。但是当在液体中应用轻敲模式时，微悬臂梁的品质因数会大幅降低，从而影响微悬臂梁的检测精度，严重时甚至使检测无法进行。因此提高品质因数成为提高液体中轻敲模式检测效果的关键。本课题分析了品质因数控制技术的原理，在此基础上设计了品质因数控制电路，并与DI公司的MultiMode SPM连接在一起构成一个完整系统。通过实验验证了品质因数控制电路的效果，从而证明了品质因数控制技术的实用性。本文的主要研究内容：分析液体中轻敲模式下AFM微悬臂梁品质因数降低的原因及提高品质因数的方法；在分析的基础上设计品质因数控制电路并与AFM连接构成一个完整的系统；在实验中验证该系统的性能；对实验结果进行分析，得出结论；更多还原

【Abstract】 Since it was invented, the measuring technology of Atomic Force Microscope(AFM) has been rapidly developed, and its applications are gradual abroad. Today, AFM has applications in physics, chemistry, metal, semiconductor, microelectronic, nanomaterial, biology, life science, and so on. At the same time, someone has made the microcantilever of AFM as sensor to detect biological and chemical reaction, and therefore AFM has become a main instrument in microscopic kingdom.There are 3 work modes in AFM, Contact Mode, Non-Contact Mode, Tapping Mode. Because it has less damage to sample, Tapping Mode has especial advantage in detecting biological and chemical reaction. However, when Tapping Mode is applied in liquid, the quality factor of microcantilever will be greatly reduced, which will reduce measuring precision of microcantilever and even make microcantilever not work. Hence increasing quality factor become the key of increasing detecting effect of Tapping Mode in liquid.In this text we have analyzed the theory of quality factor controlled, designed the circuit and linked the circuit to MultiMode SPM of DI company. We have experimented and proved our theory.Main studying content:Analyzing the reason why the quality factor of AFM microcantilever will be reduced in Tapping Mode in liquid and searching the method of increasing quality factor.Designing the circuit of quality factor controlled and linking the circuit to AFM.Proving this system’s performance in experiment.Analyzing the effect and making a conclusion.更多还原