Development of an atomic force microscope operating in DC non-contact mode

开发以直流非接触模式运行的原子力显微镜

基本信息

批准号：
07650066
负责人：
KIKUTA Hisao
金额：
$ 1.15万
依托单位：
OSAKA PREFECTURE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

The purpose was development of atomic force microscope operating in DC non-contant mode. In beginning, I have made a force feedback system with a seesaw shape lever. The lever deflection was detected by an optical lever method. The sensitivity of force measurement was -10^<-10>N.However the complex structure of the seesaw lever has caused intolerable thermal drift and a low frequency response. To overcome these problems, a novel force-feedback system using a micro-cantilever commercially available was proposed.Since the cantilever deflection is detected by a simple optical fiber interferometer, the thermal drift is reduced. And the high resonant frequency of the micro-cantilever allows the high-speed scanning of samples. The optical fiber end was coated by gold thin film. The electrostatic force between the fiber end and the gold coated micro-cantilever is balanced with the atomic force between the probe tip and sample.Some force curves were measured by using this force feedback system … More . The curves were quite different from those of conventional method in which the interaction force is determined from cantilever deflection without feedback system. Especially the maximum of the attractive force in approaching was in the same order of the maximum in going back. The stability of the system was improved, so that the force resolution was -10^<-11>N.However the frequency response was still poor because the control system used for the measurement was poor. Then I could not obtain an AFM images by scanning the sample surface.A discussion to design the feedback control system with a high frequency response was made. A simple dynamic model of cantilever was proposed in case that the probe tip was in the field of interaction force. Supposing a PID controller, the control parameters were estimated to realize the high frequency response of the feedback system.A simulation result shows a possibility of frequency response of higher than 1kHz. I will actually make the controller and will attempt to operate the AFM with non-contact DC mode. Less

目的是开发以直流非抗物模式运行的原子力显微镜。一开始，我制作了一个带有锯状杆的力反馈系统。通过光杆法检测到杠杆挠度。力测量的敏感性为-10^<-10>N。seesaw杆的复杂结构如何引起插入式热漂移和低频响应。为了克服这些问题，提出了一种新型的力量反馈系统，并提出了使用微型委托人市售的新型反馈系统。由于通过简单的光纤干扰检测到悬臂防御，因此减少了热漂移。微型委托人的高谐振频率允许对样品进行高速扫描。光纤端是通过金薄膜涂层的。纤维端和金涂层微甲板之间的静电力与探针尖端和样品之间的原子力平衡。通过使用此力反馈系统，测量了某些力曲线……更多。曲线与传统方法的曲线完全不同，在没有反馈系统的情况下，由悬臂偏转确定相互作用力。尤其是接近的吸引力的最大力量在返回时处于最大值的相同顺序。系统的稳定性得到了提高，因此力分辨率为-10^< -11> n。频率响应仍然很差，因为用于测量的对照系统很差。然后，我无法通过扫描样品表面获得AFM图像。进行了高频响应的反馈控制系统的讨论。如果探测尖端在相互作用的领域，则提出了一个简单的悬臂动态模型。假设一个PID控制器估计控制参数可以实现反馈系统的高频响应。A模拟结果显示出高于1KHz的频率响应的可能性。我实际上将制作控制器，并尝试使用非接触式直流模式操作AFM。较少的