共查询到19条相似文献,搜索用时 187 毫秒
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探针结构参数的合理选取将直接决定扫描图像及其盲探针修正图像的失真程度。基于此,以一维矩形模拟光栅为典型案例,对该模拟光栅的原子力显微镜(AFM)扫描成像过程与盲探针修正过程进行了仿真,阐明了探针结构参数对扫描成像过程与盲探针修正过程的影响规律。通过建立线宽变化度与半高宽相结合的图像重建误差评价指标,确定了针对该模拟光栅的AFM探针建议结构参数,并取得了良好的光栅图像重建效果。研究表明,应用线宽变化度结合半高宽来综合评价光栅的AFM测量和图像重建过程,有利于提升实际光栅AFM图像盲探针重建的准确度。 相似文献
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为了实现大范围纳米计量,研制了双成像单元原子力显微镜,采用光栅作参考样品,同时对光栅和被测样品扫描成像,得到两幅具有相同横向尺度的图像,通过计算参考光栅的周期数,就能精确测定被测样品图像的尺寸。提出了一种实现大范围扫描和纳米计量的新方法,利用步进电机交替移动XY扫描器,扫描获得一系列的光栅样品图像和被测样品图像对,通过拼接对应的序列图像,可获得两幅大范围的光栅图像和被测样品图像,计数参考图像中光栅的周期数,即可测定被测图像的尺度,实现对被测图像的大范围纳米计量。 相似文献
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基于精确探针模型的AFM图像重构研究 总被引:2,自引:1,他引:2
原子力显微镜技术已在纳米成像中得到了普遍应用.但实验表明,AFM图像在水平方向分辨率较低,其中探针针尖形貌是影响扫描图像分辨率的关键因素之一.为了提高AFM扫描图像的分辨率,改善成像质量,一种可行的方法是通过建立探针模型后,重构扫描图像.在已有的探针建模方法中,普遍采用盲建模算法.针对目前盲建模算法中降噪阈值难以优化问题,提出了一种降噪阈值最优估计新方法.该方法可以使盲建模算法更准确地建立扫描方向上的探针形貌轮廓,进而完成3D探针模型.通过应用AFM探针扫描多空铝和标准栅格实验,介绍了探针针尖形貌精确建模的方法.然后使用数学形态学的腐蚀运算对标准栅格的AFM成像进行了重构,验证了上述方法的有效性.实验结果证明,重构后的图像中降低了探针针尖形貌的失真影响,可以显著改善扫描探针显微镜成像的水平分辨率. 相似文献
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基于半盲解卷积复原的高分辨率视网膜成像系统 总被引:3,自引:0,他引:3
为获得高分辨率视网膜图像,建立了基于自适应光学的视网膜成像系统,并以成像时获得的残余像差作为图像复原的估计参数,通过半盲解卷积进行图像复原以获得高质量图像.通过Hartmann-Shark波前传感器和微机械薄膜变形镜组成的自适应光学系统对活体人眼像差进行测量与校正,并在成像时记录系统残余像差,据此重建光学传递函数作为图像复原模型初始参数估计,对获得的视网膜图像进行条件约束迭代半盲解卷积复原,消除像差对成像质量的影响,从而得到高分辨率视网膜图像.实验表明,系统获得的图像经该方法处理后可获得较满意视网膜图像,图像质量提高近一倍,成像成功率由38%提高至78%,成像时间缩短为原来的1/7.该方法在满足使用要求的前提下有效缩短了校正时间,提高了成像的成功率,提升了系统的适用范围. 相似文献
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为了提高原子力显微镜(Atomic Force Microscope,AFM)的成像速度,本文提出了一种新的AFM结构设计方案并搭建了相应的实验系统。在该方案中,Y、Z扫描器集成于测头内驱动探针进行慢轴扫描和形貌反馈;X扫描器与测头分离,驱动样品做快轴扫描。X扫描器采用高刚性的独立一维纳米位移台,能够承载尺寸和质量较大的样品高速往复运动而不易发生共振;同时Z扫描器的载荷实现最小化,固有频率得以显著提高。为了避免测头的扫描运动引起检测光束与探针相对位置的偏差,设计了一种随动式光杠杆光路;为了便于装卸探针以及精确调整激光在探针上的反射位置,设计了基于磁力的探针固定装置和相应的光路调节方案。对所搭建的AFM系统的初步测试结果表明,该系统在采用三角波驱动和简单PID控制算法的情况下,可搭载尺寸达数厘米且质量超过10g的较大样品实现13μm×13μm范围50Hz行频的高速成像。 相似文献
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This short paper reports a simple method to image low density lipoproteins (LDL) using atomic force microscopy (AFM). This instrument allows imaging of biological samples in liquid and presents the advantage of needing no sample preparation such as staining or fixation that may affect their general structure. Dimensions (diameter and height) of individual LDL particles were successfully measured. AFM imaging revealed that LDL have a quasi-spherical structure on the x and y axis with an oblate spheroid structure in the z axis (i.e., height). LDLs were found to have an average diameter of 23 +/- 3 nm. The obtained mean height was 10 +/- 2 nm. 相似文献
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针对当前微纳米测量中存在的大范围高精度测量及复杂微结构几何参数表征难题,基于多测头传感和精密定位平台复用技术,开发了一台具有多种测量尺度和测量模式的复合型微纳米测量仪。为使其具备大范围快速扫描测量和小范围精细测量功能,仪器集成了白光干涉和原子力显微镜两种测头,通过设计适用于两种测头集成的桥架结构及宏/微两级驱动定位平台,实现整机的开发。为保证仪器测量结果的准确性和溯源性,利用标准样板对开发完成的仪器进行了校准。仪器搭载的白光干涉测头可以达到横向500 nm,纵向1 nm的分辨力;原子力显微镜测头横向和纵向分辨力均可达到1 nm。最后,利用目标仪器对微球样品进行了测量,通过大范围成像和小范围精细扫描,获得了微球的表面特征,验证了仪器对复杂微结构的测量能力。 相似文献
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It is difficult to predict the measurement bias arising from the compliance of the atomic force microscope (AFM) probe. The issue becomes particularly important in this situation where nanometer uncertainties are sought for measurements with dimensional probes composed of flexible carbon nanotubes mounted on AFM cantilevers. We have developed a finite element model for simulating the mechanical behavior of AFM cantilevers with carbon nanotubes attached. Spring constants of both the nanotube and cantilever in two directions are calculated using the finite element method with known Young's moduli of both silicon and multiwall nanotube as input data. Compliance of the nanotube-attached AFM probe tip may be calculated from the set of spring constants. This paper presents static models that together provide a basis to estimate uncertainties in linewidth measurement using nanotubes. In particular, the interaction between a multiwall nanotube tip and a silicon sample is modeled using the Lennard-Jones theory. Snap-in and snap-out of the probe tip in a scanning mode are calculated by integrating the compliance of the probe and the sample-tip interacting force model. Cantilever and probe tip deflections and points of contact are derived for both horizontal scanning of a plateau and vertically scanning of a wall. The finite element method and the Lennard-Jones model provide a means to analyze the interaction of the probe and sample and measurement uncertainty, including actual deflection and the gap between the probe tip and the measured sample surface. 相似文献
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Based on the molecular mechanics, this study uses the two‐body potential energy function to construct a trapezoidal cantilever nano‐scale simulation measurement model of contact mode atomic force microscopy (AFM) under the constant force mode to simulate the measurement the nano‐scale V‐grooved standard sample. We investigate the error of offset distance of the cross‐section profile when using the probes with different trapezoidal cantilever probe tip radii (9.5, 8.5, and 7.5 Å) to scan the peak of the V‐grooved standard sample being reduced to one‐tenth (1/10) of its size, and use the offset error to inversely find out the regression equation. We analyze how the tip apex as well as the profile of the tip edge oblique angle and the oblique edge angle affects the offset distance. Furthermore, a probe with a larger radius of 9.5 nm is used to simulate and measure the offset error of scan curve, and acquire the regression equation. By the conversion proportion coefficient of size (ω), and revising the size‐reduced regression equation during the small size scale, a revised regression equation of a larger size scale can be acquired. The error is then reduced, further enhancing the accuracy of the AFM scanning and measurement. SCANNING 31: 147–159, 2009. © 2009 Wiley Periodicals, Inc. 相似文献
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This study constructs a contact-mode atomic force microscopy (AFM) simulation measurement model with constant force mode to simulate and analyze the outline scanning measurement by AFM. The simulation method is that when the probe passes the surface of sample, the action force of the atom of sample received by the atom of the probe can be calculated by using Morse potential. Through calculation, the equivalent force on the cantilever of probe can be acquired. By using the deflection angle equation for the cantilever of probe developed and inferred by this study, the deflection angle of receiving action force can be calculated. On the measurement point, as the deflection angle reaches a fixed deflection angle, the scan height of this simulation model can be acquired. By scanning in the right order, the scan curve of the simulation model can be obtained. By using this simulation measurement model, this study simulates and analyzes the scanning of atomic-scale surface outline. Meanwhile, focusing on the tip radii of different probes, the concept of sensitivity analysis is employed to investigate the effects of the tip radius of probe on the atomic-scale surface outline. As a result, it is found from the simulation on the atomic-scale surface that within the simulation scope of this study, when the tip radius of probe is greater than 12 nm, the effects of single atom on the scan curve of AFM can be better decreased or eliminated. 相似文献
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凸面光栅成像光谱仪的研制与应用 总被引:6,自引:2,他引:4
考虑传统光栅成像光谱仪受光学畸变的限制难以同时实现大光学孔径和小型化要求,利用全息法设计并制作了凸面光栅,并以该凸面光栅作为核心元件研制了便携式成像光谱仪。该光谱仪以推扫方式进行目标扫描,获取成像光谱数据立方。仪器的光谱分辨率为2.4 nm,光谱谱线弯曲为0.1%,色畸变为0.6%,体积为209 mm×199 mm×110 mm。介绍了仪器的工作原理和结构设计,并进行了实验室检测和室外花卉实际光谱测量。测试结果表明:凸面光栅成像光谱仪的光谱分辨率为2.1 nm,光谱谱线弯曲为0.09%,色畸变为0.6%,均满足设计要求,实际花卉光谱测试亦取得了较为理想的结果。 相似文献
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IMPROVED FABRICATION METHOD FOR CARBON NANOTUBE PROBE OF ATOMIC FORCE MICROSCOPY(AFM) 总被引:1,自引:0,他引:1
XU Zongwei DONG Shen Precision Engineering Research Institute Harbin Institute of Technology Harbin China GUO Liqiu School of Mechanical Engineering Tsinghua University Beijing China ZHAO Qingliang Precision Engineering Research Institute Harbin Institute of Technology Harbin China 《机械工程学报(英文版)》2006,19(3):373-375
An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy (AFM) here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two high precision microtranslators. When silicon probe and carbon nanotube are very close, several tens voltage is applied between them. And carbon nanotube is divided and attached to the end of silicon probe, which mainly due to the arc welding function. Comparing with the arc discharge method before, the new method here needs no coat silicon probe with metal film in advance, which can greatly reduce the fabrication's difficulty. The fabricated carbon nanotube probe shows good property of higher aspect ratio and can more accurately reflect the true topography of silicon grating than silicon probe. Under the same image drive force, carbon nanotube probe had less indentation depth on soft triblock copolymer sample than silicon probe. This showed that carbon nanotube probe has lower spring constant and less damage to the scan sample than silicon probe. 相似文献
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Atomic force microscopy has been used to visualize nano‐scale structures of various cellular components and to characterize mechanical properties of biomolecules. In spite of its ability to measure non‐fixed samples in liquid, the application of AFM for living cell manipulation has been hampered by the lack of knowledge of the mechanical properties of living cells. In this study, we successfully combine AFM imaging and force measurement to characterize the mechanical properties of the plasma membrane and the nuclear envelope of living HeLa cells in a culture medium. We examine cantilevers with different physical properties (spring constant, tip angle and length) to find out the one suitable for living cell imaging and manipulation. Our results of elasticity measurement revealed that both the plasma membrane and the nuclear envelope are soft enough to absorb a large deformation by the AFM probe. The penetrations of the plasma membrane and the nuclear envelope were possible when the probe indents the cell membranes far down close to a hard glass surface. These results provide useful information to the development of single‐cell manipulation techniques. 相似文献