扫描隧道显微镜和原子力显微镜

介绍了扫描隧道显微镜(STM)和原子力显微镜(AFM)的原理和目前情况。     

卧式原子力显微镜的研制

提出原子力显微镜 (AFM)的新设计 ,讨论卧式 AFM的工作原理及其性能特点 ,简要介绍 AFM的控制电路系统及其图像扫描和图像处理软件系统 ,给出 AFM扫描获得的部分样品的图像结果。     

高速大扫描范围原子力显微镜系统的设计

针对目前高速扫描型原子力显微镜(AFM)主要是限于物检测且扫描速度和扫描范围均有待提高,提出了一种高速原子力显微镜结构设计方案。在压电陶瓷致动器驱动的柔性铰链结构式位移台的基础上,构建了AFM大范围扫描器,使原子力显微镜在x-y扫描方向的运动范围达到了100μm×100μm。通过傅里叶频谱分析,计算获得了AFM扫描器常用的三角波驱动信号和正弦波驱动信号的高次谐波特性及其对AFM高速扫描成像的影响程度。为了消除在扫描运动过程中的机械自激振荡,提出了将正弦波信号作为高速扫描的驱动信号,行扫速度达到50line/s。在正弦波驱动的基础上提出了一种基于位置采样的图像获取方法,有效地减小了AFM扫描器的非线性误差造成的图像畸变现象。     

一种高精度多功能双用原子力显微镜技术及应用

主要研究了一种基于高精度IPC-205B型扫描隧道显微镜(STM)的新型高精度多功能双用原子力显微镜(AFM)技术及其应用.阐述该原子力显微镜的工作原理、组成及应用,详细介绍了该AFM镜体的独特结构和新型微悬臂的制作及其检测方法.该AFM采用简单适用的新型微悬臂.并利用STM检测微悬臂的起伏,通过四维机械驱动和双压电陶瓷扫描,有效提高了扫描精度,扩大了扫描范围.该机型集AFM和STM功能为一体,其中STM可以单独使用.该机型检测精度可达:横向0.1 nm,纵向0.01 nm.并用该样机进行了样品表面形貌和隧道谱的实验研究.     

基于小波变换的AFM图像处理的研究

根据原子力显微镜(AFM)图像的特点，对小波变换应用于原子力显微镜图像的降噪、增强及融合方法进行了阐述，采用原子力显微镜对无磨料低温抛光后的铝合金(LY12)表面进行检测，并利用所述方法对扫描图像进行了处理。结果表明，利用小波变换对原子力显微镜图像进行处理是有效的、可行的，图像质量得到明显提高。     

小波变换在AFM图像处理中的应用研究

根据原子力显微镜(AFM)图像的特点,对小波变换应用于原子力显微镜图像的降噪、增强及融合方法进行了阐 述,采用原子力显微镜对无磨料低温抛光后的铝合金(LY12)工件表面进行检测,并利用所述方法对扫描图像进行了处 理。结果表明,利用小波变换对原子力显微镜图像进行处理是有效的、可行的,得到满意效果。     

磁控溅射沉积氧化锌薄膜的原子力显微镜研究

用扫描原子力显微镜(AFM)研究了射频磁控溅射工艺参数(功率、放电气体压力、氧气分压强等)对ZnO透明导电薄膜微结构的影响。     

湿度对液桥中毛细力和能量耗散的影响

原子力显微镜(AFM)在扫描图像过程中会产生赝像的重要因素是:在探针和基底表面接触过程中,两者之间会生成一种带有黏附力的结构,称之为液桥。在大气环境下,不同的湿度条件能够影响液桥的形成和断裂,而液桥的存在会使得原子力显微镜在扫描成像过程中,悬臂梁自由端的受力和能量产生变化,最终干扰扫描成像的质量。研究不同湿度对于针尖和基底之间的毛细力F_(max)、能量耗散η的影响,选择最佳的成像条件,可以提高AFM工作的准确性和可靠性。     

原子力与扫描隧道组合显微镜

由大连理工大学物理系研制的原子力与扫描隧道组合显微镜 ( AF/ PSTM) ,9月 2 3日通过了国家教育部组织的鉴定。鉴定委员会对该成果给予了高度评价。该仪器是同时具有纳米分辨原子力显微镜和纳米分辨光学显微镜双重功能图像分解的纳米成像仪器。仪器技术原理是在 AF/ PSTM中设置一个双功能共振光纤尖 ,当光纤尖在样品表面近场扫描时 ,反馈控制等振幅扫描成像 ,一次扫描中 ,同时采集样品的原子力显微镜 AFM图像和光子扫描隧道显微镜PSTM图像。该仪器在分子生物学、医药学、新材料学、集成光学、纳米科技等领域均很有用 ,高校将来甚至…     

SPM技术在碳纤维结构研究上的应用

简单介绍了系列扫描探针显微镜（SPM）的性能、原理及其应用,重点综述了SPM尤其是扫描隧道显微镜（STM）和原子力显微镜（AFM）在碳纤维结构研究领域中的应用。     

Analysis of friction and surface roughness effects on edge crack evolution of thin strip during cold rolling

Experimental investigation and mechanical analysis have been carried out to study the edge crack formation during cold strip rolling using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The effects of friction and surface roughness on edge crack initiation and growth rate have been discussed. Friction leads to an increase in fracture loads and decreasing the friction coefficient is effective in preventing the microcracks. Surface roughness variation along the strip width contributes to stress distribution and inhibits crack nucleation. The findings reveal that the behaviour of crack evolution is influenced by fracture surface roughness as well as rolling friction.     

Imaging the cell surface: argon sputtering to expose inner cell structures

Established microscopies such as Scanning Electron Microscopy (SEM) and more recent developments such as Atomic Force Microscopy (AFM) and X-ray Photo-Electron Emission spectroMicroscopy (X-PEEM) can only image the sample surface. We present an argon sputtering method able to progressively expose inner cell structures without apparent damage. By varying the sputtering time, the structure of cell cytoskeleton, vesicles, mitochondria, nuclear membrane, and nucleoli can be imaged. We compared images obtained with confocal fluorescence microscopy, transmission electron microscopy (TEM), SEM, and X-PEEM on similar samples after argon sputtering, then confirmed the similarity of reference intracellular structures, including cytoskeleton fibers, cell-cell and cell-substrate adhesion structures, and secretory vesicles. We conclude that the sputtering method is a new valuable tool for surface sensitive microscopies.     

Analysis of effect of nanoporous alumina substrate coated with polypyrrole nanowire on cell morphology based on AFM topography

In this study, in situ electrochemical synthesis of polypyrrole nanowires with nanoporous alumina template was described. The formation of highly ordered porous alumina substrate was demonstrated with Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). In addition, Fourier transform infrared analysis confirmed that polypyrrole (PP) nanowires were synthesized by direct electrochemical oxidation of pyrrole. HeLa cancer cells and HMCF normal cells were immobilized on the polypyrrole nanowires/nanoporous alumina substrates to determine the effects of the substrate on the cell morphology, adhesion and proliferation as well as the biocompatibility of the substrate. Cell adhesion and proliferation were characterized using a standard MTT assay. The effects of the polypyrrole nanowires/nanoporous alumina substrate on the cell morphology were studied by AFM. The nanoporous alumina coated with polypyrrole nanowires was found to exhibit better cell adhesion and proliferation than polystyrene petridish, aluminum foil, 1st anodized and uncoated 2nd anodized alumina substrate. This study showed the potential of the polypyrrole nanowires/nanoporous alumina substrate as biocompatibility electroactive polymer substrate for both healthy and cancer cell cultures applications.     

Fabrication of Au nanodots with 60 nm diameter on ITO glass: Towards nanobiochip using nanoporous alumina mask

Au nanodots can be utilized for the fabrication of protein nanoarrays. Au nanodots were fabricated on ITO glass by the thermal evaporation method using nanoporous alumina as a shadow mask. Uniform Au nanodots with a diameter of 60 nm were formed on the ITO glass as a replica of the alumina mask. The morphology of the Au nanodots was verified by Field Emission Scanning Electron Microscopy (FE-SEM). Cysteine-modified azurins were immobilized on the Au nanodots. The topography of the proteins immobilized on the Au nanodots was investigated by atomic force microscopy (AFM) in tapping mode. These Au dot arrays can be potentially utilized as usable elements to construct nanobiochips.     

The influence of AFM and VSI techniques on the accurate calculation of tribological surface roughness parameters

Vertical Scanning Interferometry (VSI) may induce optical artefacts in surface topography measurements. The influence of these optical artefacts on the calculation of R_k surface roughness parameters, contact stiffness and flow factors were studied. Two surface measurement techniques were used: Atomic Force Microscopy (AFM) and VSI. Calibration grids were used to make it easier to isolate the causes of these artefacts, while a real engineering surface was used to compare these two techniques in an industrially applied case. It was found that the optical artefacts have a large influence on all the roughness parameters, contact stiffness and flow factors calculated on the calibration grids. However, for the engineering surface the differences between AFM and VSI measurements were much smaller.     

STM和AFM的研制

叙述ＳＴＭ（扫描隧道显微镜）和ＡＦＭ（原子力显微镜）的主要关键技术和研制情况。在研制的ＳＴＭ和ＡＦＭ样机上，对１２００１／ｍｍ光栅进行测量，得出本样机的测量重复性可达１０％以内。对研制的样机进行分析和对比后提出：ＳＴＭ和ＡＦＭ，尤其是ＡＦＭ，技术上已趋于成熟；使用上简单、方便，已达到实用化程度，可以作为高级表面粗糙度测量的常用计量仪器。     

A ‘3-body’ abrasion wear study of bioceramics for total hip joint replacements

The current study focuses on the effect of the material type and the lubricant on the abrasive wear behaviour of two important commercially available ceramic on ceramic prosthetic systems, namely, Biolox^® forte and Biolox^® delta (CeramTec AG, Germany). A standard microabrasion wear apparatus was used to produce ‘3-body’ abrasive wear scars with three different lubricants: ultrapure water, 25 vol% new-born calf serum solution and 1 wt% carboxymethyl cellulose sodium salt (CMC-Na) solution. 1 μm alumina particles were used as the abrasive. The morphology of the wear scar was examined in detail using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Subsurface damage accumulation was investigated by Focused Ion Beam (FIB) cross-sectional milling and Transmission Electron Microscopy (TEM). The effect of the lubricant on the ‘3-body’ abrasive wear mechanisms is discussed and the effect of material properties compared.     

Investigation of the Mending Effect and Mechanism of Copper Nano-Particles on a Tribologically Stressed Surface

The mending effect and mechanism of metal nano-particles in an area undergoing wear are quite important for both the fundamental theory of nano-tribology and the development of lubricant additives. This paper presents research on the mending effect of copper nano-particles added to lubricant oil. Pin-on-disk experiments and Scanning Electron Microscopy (SEM) observations show that copper nano-particles do display an excellent mending effect. The observation by Scanning Tunnelling Microscopy (STM) reveals that the mending effect results from the deposition of copper nano-particles onto the wear scar. It has also been disclosed by heating simulation that, due to nano-scale effects, which bring about decrease in the diffusion temperature of copper nano-particles, the heat generated by friction leads to the diffusion of copper nano-particles and their subsequent deposition, which finally results in the so-called mending effect.     

Electron tomography combining ESEM and STEM: a new 3D imaging technique

This paper presents the development and the application of a new electron tomography technique based on STEM (Scanning Transmission Electron Microscopy) configuration in ESEM (Environmental Scanning Electron Microscopy). This combination provides a new approach for the characterization of the 3D structure of materials, as it optimizes a compromise between the resolution level of a few tens of nm and the large tomogram size due to the high thickness of transparency. The method is well adapted for non-conductive samples, and exhibits good contrast even for materials with low atomic number. The paper describes the development of a dedicated stage for this new tomography technique. Taking advantage of the size of the ESEM chamber, the range of tilt angles is not limited by the space around the sample. The performance of this device is illustrated through the three-dimensional characterization of samples issued from materials science and chosen to illustrate the results in resolution, contrast and thickness.     

激光共焦扫描显微镜简介

激光共焦扫描显微镜是显微光学技术发展史上的新里程碑,它集激光技术、光学技术、电子计算机技术,作为现代化的显微成像系统倍受广大科研工作者的关注,并在生命科学、材料科学等领域中具有广泛的应用。本文就激光共焦扫描显微镜的主要技术特点作综合性介绍。