Atomic Force Spectroscopy using a force balance technique

使用力平衡技术的原子力光谱

基本信息

批准号：
09650066
负责人：
KIKUTA Hisao
金额：
$ 2.24万
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：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650066/
关键词：
Atomic force microscope Atomic force spectroscopy Force curve Force balance method feedback control Polymer cantilever 力曲線力制御減衰係数力バランス

项目摘要

The aim of this study was fabrication of an atomic force spectroscope with a force balancing method for surface characterizations. Some research groups had tried to measure force curves accurately by using the force balancing method, but they did not succeeded in it. In this study, we analyzed a system stability based on the feedback control theory, and it was cleared that the difficulty of measuring the force curves was caused by an insufficient frequency response of the feedback controller. When we use a AFM micro-cantilever commercially sold, the feedback controller must have frequency response of 〜100MHz. Such a frequency response is too fast to be performed by digital computer. An analog amplifier which has an enough frequency response also is of no use in the force curve measurement because of an increasing in noise level and the limit of force actuator's response.The required bandwidth of the feedback controller can be reduced by a micro-cantilever with a high damping coefficient. Then we discussed some ways to increase the damping coefficient of the micro-cantilever by changing material and an atmosphere. Consequently a plastic micro-cantilever, especially polyimide resin, is valid to increase the coefficient. A polyimide micro-cantilever was fabricated with a micro-lithography technology and its mechanical properties were investigated experimentally. From a numerical simulation based on the mechanical properties of the polyimide resin, we found that an amplifier with 1MHz bandwidth was usable to the force-balancing system. Moreover polyimide has a good heat proof, which is suitable for measurement in a ultra-high vacuum.We fabricated a polyimide micro-cantilever with a probe tip and a PID feedback controller with 1MHz bandwidth. However we have not measured the force curves in the term of this project.

这项研究的目的是制造具有表面特征的力平衡方法的原子力光谱。一些研究小组试图通过使用力平衡方法准确地测量力曲线，但他们没有成功。在这项研究中，我们根据反馈控制理论分析了系统稳定性，并清除测量力曲线的困难是由反馈控制器的频率响应不足引起的。当我们使用商业出售的AFM微型委托人时，反馈控制器的频率响应必须约为100MHz。这样的频率响应太快了，无法通过数字计算机执行。具有足够频率响应的模拟放大器在力曲线测量中也无用，因为噪声水平的升高和力执行器的响应极限。反馈控制器所需的带宽可以通过具有高阻尼系数的微型委托人降低。然后，我们讨论了通过改变材料和气氛来增加微型委托人的舞蹈核心的一些方法。因此，塑料微抗肽，尤其是聚酰亚胺树脂，有效增加核心。用微型印刷技术制造了聚酰亚胺微型委托人，并通过实验研究了其机械性能。从基于聚酰亚胺树脂的机械性能的数值模拟中，我们发现具有1MHz带宽的放大器可用于力平衡系统。此外，聚酰亚胺具有良好的防热，适用于在超高真空中测量。我们制造了带有探针尖端的聚酰亚胺微型 - 局体和带有1MHz带宽的PID反馈控制器。但是，我们尚未在该项目的任期内测量力曲线。