共查询到17条相似文献,搜索用时 989 毫秒
1.
设计了一种小型轻敲式自感应原子力显微镜(AFM)测头以实现微/纳尺度下的几何量测量.轻敲式测头采用石英音叉式自感应探针,通过自身的电信号输出检测悬臂梁的振幅变化,无需额外的光学传感器.设计了测头的微弱自感应信号放大电路,并补偿音叉寄生电容对测量的干扰.机械结构紧凑便于将测头固定于光学显微镜下观察测量情况,同时屏蔽外界的干扰.利用显微激光多普勒测振系统,标定了测头机电耦合系数为145 nm/V,由此可以计算测头工作频率下悬臂梁的振幅.搭建了以纳米测量机(NMM)为高精度定位平台的测试系统,利用该系统对测头进行进/退针实验,标定测头的灵敏度为0.47 nm/mV,NMM内置的干涉仪保证标定直接溯源至"米"定义.实验表明测头的非线性误差小于1%,测量范围在百纳米级. 相似文献
2.
3.
4.
5.
6.
7.
《纳米技术与精密工程》2017,(2)
设计并制作了一种适用于原位纳米力学测试的原子力显微镜(AFM)测头.测头由光学检测系统和Z向压电陶瓷微位移机构组成.其中光学检测系统采用光杠杆与显微镜同轴光路检测探针形变,压电位移机构内置电容传感器可实现探针进给量的闭环控制.标定实验表明该测头闭环位移分辨力优于10 nm,在标定范围内具有很好的线性.利用该测头对某型微悬臂梁法向弹性常数进行了测量,测得值与采用具有溯源性的标定方法所得结果一致. 相似文献
8.
9.
原子力显微镜(AFM)对样品进行测量时,探针针尖与样品表面接近过程中的微观作用力探测是实现样品形貌准确测量的基础。本文基于音叉式探针的特性建立探针针尖与样品表面接近过程中的动力学方程,并利用simulink软件模拟了上述过程中探针悬臂振幅响应情况。自主搭建了基于音叉探针的接近曲线检测装置,编写位移系统控制程序和锁相放大器数据采集程序,在调幅模式下获得探针在不同激励电压下的接近曲线,其形式与仿真相符。研究结果将为音叉式原子力显微系统的搭建及优化反馈控制的设计提供扫描基准参考。 相似文献
10.
《纳米技术与精密工程》2016,(2)
传统原子力显微镜(AFM)在接触模式下工作时具有接触力较大、易损伤样品的缺点.本文通过对新型自感应音叉探针施加双频激励,使得AFM工作在轻敲模式下,减小了接触力和扫描过程中的侧向力影响,实现了样品表面力学特性和亚表面结构的表征.然后利用基于DSP的PI反馈控制模块,完成了线扫描实验,证明该双频原子力显微测量系统具有较好的测量能力. 相似文献
11.
A technique that combines scanning electrochemical microscopy (SECM) and scanning optical microscopy (OM) was developed. Simultaneous scanning electrochemical/optical microscopy (SECM/OM) was performed by a special probe tip, which consists of an optical fiber core for light passage, surrounded by a gold ring electrode, and an outermost electrophoretic insulating sheath, with the tip attached to a tuning fork. To regulate the tip-substrate distance, either the shear force or the SECM tip current was employed as the feedback signal. The application of a quartz crystal tuning fork (32.768 kHz) for sensing shear force allowed simultaneous topographic, along with SECM and optical imaging in a constant-force mode. The capability of this technique was confirmed by obtaining simultaneously, for the first time, topographic, electrochemical, and optical images of an interdigitated array electrode. Current feedback from SECM also provided simultaneous electrochemical and optical images of relatively soft samples, such as a polycarbonate membrane filter and living diatoms in a constant-current mode. This mode should be useful in mapping the biochemical activity of a living cell. 相似文献
12.
Labardi M 《Nanotechnology》2007,18(39):395505
The dynamics of force microscopy probes attached to quartz tuning fork piezoelectric sensors has been investigated, by simply modeling the tuning fork/probe system as two coupled damped harmonic oscillators. Depending on how probes are applied to the tuning fork prong, they could show appreciable compliance along the direction of approach to the surface. In particular, buckling or bending deformation of the probe may account for unexpectedly long interaction ranges found in experimental approach curves. Some peculiar curves found in the literature in the case of lateral probe oscillation (shear force) are well reproduced by the present model. In particular, a 'clamping' effect is observed when the probe is substantially more compliant than the tuning fork. By calculating the actual probe motion along with the tuning fork response, the correct distance control operation regimes are pointed out for the shear-force case, even when using compliant probes. The model can be readily extended to the case of normal oscillation, at least for small amplitudes. Furthermore, it could be applied to a 'mixed' case of shear-force detection performed with very compliant probes. The present analysis can help to improve data interpretation and operation conditions in dynamic force microscopy and spectroscopy. 相似文献
13.
Vo Thanh Tung S. A. Chizhik Tran Xuan Hoai 《Journal of Engineering Physics and Thermophysics》2009,82(1):140-148
A quartz tuning fork-based atomic force microscopy for investigating the tip–sample interactions at the nanoscale in the shear-force
mode is described. Results of force interactions (damping and elastic forces) can be obtained from the amplitude-phase-distance
spectroscopy measurements made with a tuning fork with a tungsten tip and a sample surface. The influence of the interaction
between tip and sample using the quality factor as an indicator is investigated. Furthermore, a simple model shows that the
extension of a tuning fork-based AFM can be applied to quantitative analysis of the properties of the sample surface.
Published in Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 1, pp. 141–149, January–February, 2009. 相似文献
14.
15.
Four-terminal electrical measurement is realized on a microscopic structure in air, without a lithographic process, using a home-built quadruple-scanning-probe force microscope (QSPFM). The QSPFM has four probes whose positions are individually controlled by obtaining images of a sample in the manner of atomic force microscopy (AFM), and uses the probes as contacting electrodes for electrical measurements. A specially arranged tuning fork probe (TFP) is used as a self-detection force sensor to operate each probe in a frequency modulation AFM mode, resulting in simultaneous imaging of the same microscopic feature on an insulator using the four TFPs. Four-terminal electrical measurement is then demonstrated in air by placing each probe electrode in contact with a graphene flake exfoliated on a silicon dioxide film, and the sheet resistance of the flake is measured by the van der Pauw method. The present work shows that the QSPFM has the potential to measure the intrinsic electrical properties of a wide range of microscopic materials in situ without electrode fabrication. 相似文献
16.
A combined scanning electrochemical microscope (SECM)-atomic force microscope (AFM) is described. The instrument permits the first simultaneous topographical and electrochemical measurements at surfaces, under fluid, with high spatial resolution. Simple probe tips suitable for SECM-AFM, have been fabricated by coating flattened and etched Pt microwires with insulating, electrophoretically deposited paint. The flattened portion of the probe provides a flexible cantilever (force sensor), while the coating insulates the probe such that only the tip end (electrode) is exposed to the solution. The SECM-AFM technique is illustrated with simultaneous electrochemical-probe deflection approach curves, simultaneous topographical and electrochemical imaging studies of track-etched polycarbonate ultrafiltration membranes, and etching studies of crystal surfaces. 相似文献
17.
Ability to determine local electric surface properties with a high resolution is a key issue in many modern industrial applications. In this article, authors will describe low-cost and reliable methods for investigations of electrical surface properties with a nanoscale resolution using a homebuilt modular tunneling/atomic force microscope with a quartz tuning fork as a probe. We will present the architecture of the designed system and the calibration method of the applied sensor. In our work, the usage of the tunneling atomic force microscope in the high-resolution investigations of the surface topography and identification of local spots where the tunneling current is observed will be demonstrated. We will also present current-voltage (I-V) spectroscopy performed on a gold thin film sputtered on silicon substrate and a highly oriented pyrolitic graphite (HOPG) surface, which we obtained in air ambient and at room temperature. 相似文献