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原子力显微镜在液相条件下的成像分析 总被引:1,自引:0,他引:1
本研究利用原子力显微镜(atomic force microscope,AFM)分别对Al2O3纳米模板、云母片及数字光盘在固相及液相务件下进行形貌扫描和云母片上的力 - 距离曲线测量.实验结果分析表明液相条件可以降低针尖的展宽效应,使得形貌成像更能够显示出物体的细微结构.在液相条件下,由于样品表面消除了静电效应和液体的阻滞力结果,力 - 距离曲线显示了较好的力均一性.这些结果为AFM实验技术研究生理条件下的生物样品的形态学及生物分子之间的相互作用力提供了实验可行性. 相似文献
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A model of mechanical behavior of microcantilever due to mismatch strain during deposition of MEMS structures is derived. First, a microcantilever, modeled as an Euler-Bernoulli beam, is subjected to deposition of another material and a linear ordinary differential equation which considers the through-thickness variation of the mismatch strain is derived. Second, the deposition analysis is experimentally realized by electroplating of nickel onto an atomic force microscope (AFM) cantilever beam. Young's modulus of the electroplated nickel film is determined by using Sader's method and elementary beam theory. The deflection of the AFM cantilever is in-situ measured as a function of the electroplated thin film thickness through the optical method of AFM and the mismatch strain with the through-thickness variation is determined from the experiment results. 相似文献
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分析了阵列悬臂探针并行扫描的工作方式,以非接触磁力模拟样品与悬臂梁间的范德华力,研究了1×2阵列压电悬臂梁的并行扫描和驱动控制方法。每一压电梁均集成了微位移致动器和力传感器,在320Hz一阶共振频率下振动。实验表明:在0.2~1.0mm力作用区内,压电梁自由端每接近模拟样品0.1mm,表征悬臂梁振幅的锁相放大器输出电压减小1.7mV,但微力传感在扫描的升回程存在迟滞;致动器的控制电压每增加10V使锁相放大器输出减小约3mV,表明集成的致动器可调节压电梁与样品间的间距。两压电梁的电荷-位移响应曲线、间距调节灵敏度均不完全一致,讨论了阵列悬臂梁一致性问题和阵列规模大小问题。 相似文献
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目前商用原子力显微镜(AFM)大多使用的微悬臂式探针,力灵敏度可达到pN级别。然而受到工艺水平及检测方法限制,微悬臂谐振频率难以超过3.5 MHz,且Q值较低,制约了AFM的成像速度以及在液体中的成像效果。另外,光杠杆的检测方法无法与探针本身进行片上集成,较小的悬臂也给激光束的聚焦带来困难。基于以上考虑,本文提出两种基于MEMS谐振器的探针,振频率可达11 MHz,Q值为4 000,并集成了执行与传感功能以及批量加工纳米针尖的工艺。目前两种探针都已经实现对树脂图案的成像功能,力灵敏度最高可达5pN/√Hz。 相似文献
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A new approach based on microcantilevers is presented to detect infrared photons with high sensitivity. Infrared photons are measured by monitoring the amplitude change of a vibrating microcantilever under light pressure force.The irradiating light is modulated into sinusoidal and pulsed waves,and to be in-phase and anti-phase with the cantilever driving signal.A linear relationship between the amplitude change of the cantilever and the light power distributing on the cantilever was observed.Under a vacuum of 10-4 Pa,an infrared light power of 7.4 nW was detected with the cantilever.The in-phase and anti-phase modulation to the cantilever vibration using a pulsed light results in an enhanced response of the cantilever. 相似文献
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在轻敲工作模式下,原子力显微镜(AFM)压电微悬臂以较大的振幅振动。以纳米管针尖为例建立了压电微悬臂振动的数学模型并描述了纳米管尖端的振动轨迹,从纳米管尖端的振动轨迹和仿真图形的关系,指出压电微悬臂振动影响测量精度的有关参数及减小由振动产生膨胀变形的方法。根据数学图形学膨胀理论仿真出纳米管尖端振动轨迹对标准线宽模型的影响,AFM测量线宽的试验验证了上述结果。 相似文献
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《Signal Processing Magazine, IEEE》2007,24(1):122-125
In this article, we discuss the design of a smart-physics-based processor for microcantilever sensor arrays. The processor is coupled to a microelectromechanical sensor and estimates the presence of critical materials or chemicals in solution. We first briefly present microcantilever sensors and then discuss the microcantilever sensor array design, which consists of the cantilever physics propagation model, cantilever array measurement model, model-based parameter estimator design, and model-based processor (MBP) design. Finally, we end with experimental results and conclusions 相似文献
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给出了自制的 3mm× 3mm位置敏感元件 (PSD)的光谱响应特性 ,覆盖从紫外光、可见光到红外光 (32 0~115 0nm)的广阔区域 .采用光束偏转法对其时间响应特性和位置敏感特性进行测定 .阐述了PSD在卧式原子力显微镜 (AFM)系统中的应用 ,介绍了卧式AFM的工作原理和控制系统 ,提供了部分样品的AFM扫描图像 .结果表明 ,该AFM系统具有较高的成像效率以及良好的工作稳定性、图像重复性和对比度 ,系统的最大扫描范围为 5 μm× 5 μm ,分辨率达到 1nm量级 ,表明PSD在光谱响应、时间响应和位置敏感特性等方面具有优良性能 相似文献
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This paper presents the design, fabrication, and implementation of a microcantilever actuator with magnetostatic latching for performing low power bistable relay applications. This unique bistable feature consists of a low-stiffness torsion/cantilever beam system with circular-shaped support and a permanent magnet for holding the closed state with a permalloy soft magnetic circuit. The special circular support is designed to enhance the stiffness of the overhang beams. First, mechanical modeling of the leveraged torsion/cantilever beams was performed by Castigliano’s theorem so as to deduce the spring stiffness of system. Then the device has been prepared by a laminated photoresist sacrificial layer process (LPSLP). Finally, mechanical performance was characterized by atomic force microscopy (AFM), combined with finite element simulation using ANSYS™ package and analysis model as well. Switching between two stable states of the microactuator was successfully validated with WYKO NT1100 optical profiling system. 相似文献
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Several methods have been developed in recent years to calibrate the spring constant of atomic force microscopy (AFM) cantilever. In the present work, an effective and practical improvement is made on these methods to provide a more convenient calibration method. Simplifying the originally tedious procedures by just examining the cantilever's dimensions in scanning electron microscopy (SEM) and the resonance frequency of the cantilever from Q curves in AFM system, the spring constants of different cantilevers are calculated by the methods of Cleveland and Sader. The results are close to the nominal values provided by the manufacturers, which indicates that simplifying the procedures is valid and reliable. Moreover, it shows that spring constants acquiring by Cleveland method is more close to their nominal values than Sader's method does. 相似文献
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Sensitivity of V-shaped atomic force microscope cantilevers based on a modified couple stress theory
Haw-Long LeeWin-Jin Chang 《Microelectronic Engineering》2011,88(11):3214-3218
A relationship based on a modified couple stress theory is developed to investigate the flexural sensitivity of a V-shaped cantilever of an atomic force microscope (AFM) taking into account the normal interaction force between the cantilever tip and the sample surface. An approximate solution to the flexural vibration problem is obtained using the Rayleigh-Ritz method. The results show that the sensitivity of the V-shaped AFM cantilever using the modified couple stress theory is smaller than that using the classical beam theory for the lower contact stiffness. However, when the contact stiffness becomes higher, the situation is reversed. Furthermore, as the ratio of cantilever thickness to internal material length scale parameter decreases, the sensitivity of the cantilever decreases. 相似文献