纳米定位技术的发展现状

超精密位置控制技术是超精密加工和测量的基础。通过对现有几种具有纳米分辨率的驱动系统进行比较,分析了各种定位系统的特点,展望了纳米定位技术的发展方向。     

纳米定位机构及其控制系统的研究

在纳米科学与技术领域 ,纳米定位技术是纳米测量和原子操作工程研究及走向产业化的前提条件和工作基础。本文设计了一种新颖的以柔性铰链为弹性导轨、压电陶瓷为驱动器的纳米定位机构 ,给出了其动力学模型 ,结合纳米传感器微位移检测装置和微机控制系统设计并研制了数字闭环控制的纳米定位系统。实验表明 :该纳米定位系统行程 10 μm ,定位精度优于± 0 .0 3μm ,定位分辨力 3nm ,最大定位时间 40ms。     

纳米操作系统的研究现状与关键技术

纳米操作是用于研究纳米材料、结构和装置的性质特征的基本技术,也是纳米构筑单元准备、纳米设备装配的必备技术。目前典型的纳米操作系统有基于扫描探针显微镜的系统,基于电子显微镜的系统,基于光镊的系统及混合式系统。详细阐述了各类系统的特点和发展现状。分析了末端工具、显微成像、定位与驱动、操作策略等纳米操作系统中的关键技术,并对发展趋势进行了展望。     

纳米压痕技术研究现状与发展趋势

纳米压痕技术是一种新的材料特性测量方法,被广泛应用在研究微/纳零部件的力学性能和材料微纳区域内的局部特性。介绍了纳米压痕技术的基本理论方法;针对纳米压痕技术的理论建模、压痕形貌、微观组织以及测量精度等几个方面对现有的研究成果进行系统的分析和总结;分析了纳米压痕技术现存的研究难点及主要问题,并对其发展趋势进行了展望。     

纳米流体制备技术与组成结构的研究进展

纳米流体作为一种新型换热工质日益受到科研及工程技术人员的高度关注,但纳米流体的不稳定性是阻碍其广泛应用的技术瓶颈。针对这一问题,目前已经取得了许多重要的研究成果。本文从纳米流体的制备方法、纳米流体的分散措施、纳米流体悬浮稳定性分析、纳米流体的聚集结构等几个方面对当前纳米流体的制备技术与组成结构的国内外最新研究成果进行了介绍,并从制备高稳定性纳米流体的目标提出了对今后研究重点的建议。     

基于光栅干涉相位移动扫描的超精密测量方法

精密定位技术作为精密制造和精密装备的基础,一直制约着我国精密制造和精密装备产业的发展,而纳米级的位移测量技术又是制约精密定位技术发展的一个重要原因.研究了一种基于光栅干涉相位移动扫描原理的纳米级位移测量系统,利用光栅干涉仪实现光学四倍频,再利用条纹移相机构实现信号的进一步细分,获得亚纳米级的测量分辨率.     

纳米压痕技术及其应用

介绍纳米压痕的一般要领及纳米压痕系统的组成，阐述纳米压痕技术在几个方面的具体应用。     

纳米定位技术的进展

综述了纳米定位技术现状及未来,讨论了影响其发展因素。     

纳米实验力学中的相关测试技术

材料纳观力学特性与纳米材料力学特性的测试是纳米实验力学的基本内容。本文对纳米硬度技术、纳米云纹技术、扫描力显微镜(SFM)技术等主要的几种纳米实验力学测试技术进行概述,然后对目前纳米碳管力学特性试验测试的若干方法进行介绍。     

纳米测量系统的研究现状与展望

本文介绍了纳米测量系统的各个组成部分,即探测系统、位移系统、计量系统、信号处理及控制系统,综述了国内外的研究状况和相关产品,在此基础上提出了一种集驱动、定位、测量、伺服控制、信号处理等技术于一体的实用型二维纳米测量技术,并对其应用前景作了展望.     

三维纳米级微动工作台的设计与分析

研究开发了一种新型精密三维微动工作台。采用呈等边三角形分布的三个压电陶瓷和环形平板铰链机构 ,保证了运动传递的连续性、无洄滞、无摩擦、高精度。建立了工作台的简化模型,并利用结构力学理论推导出工作台沿z方向平动刚度、绕x、y方向转动刚度以及前三阶固有频率解析式。进行了微动工作台沿z方向平动刚度、绕x、y方向转动刚度以及固有频率试验测试,验证了解析方法和有限元方法进行三维工作台刚度及动力特性分析的正确性。有限元分析表明:当工作台的环形平板铰链半径较小而铰链厚度较大时,其刚度、频率及驱动力较高,其铰链根部应力集中也较严重。通过改变环形平板铰链的特征参数,可达到控制和优化工作台固有频率、输出位移、应力分布及驱动力响应的目的,并提出了一种优选微动工作台环形平板铰链参数的简易方法。     

一种纳米级二维微定位工作台的设计与分析

研究开发了一种采用柔性铰链导向的二维光学调整微定位工作台,建立了工作台的简化模型,并利用结构力学理论推导出工作台沿x、y方向刚度及前二阶固有频率解析式。进行了微定位工作台固有频率及沿x、y方向刚度的试验测试,并结合解析方法和有限元方法对微定位工作台设计刚度及动力特性进行分析验证。有限元分析表明:当工作台的直角平板柔性铰链长度较小而铰链宽度较大时,其刚度、频率及驱动力较高,铰链根部应力集中也较严重。通过改变柔性铰链的特征参数,可达到控制和优化工作台固有频率、输出位移、应力分布及驱动力响应的目的,并提出了一种优选微定位工作台柔性铰链参数的简易方法。     

Three-dimensional nanopositioning and nanomeasuring machine with a resolution of 0.1 nm

The paper describes traceable nanometrology based on a nanopositioning machine with integrated nanoprobes. The operation of a high-precision long-range three-dimensional nanopositioning and nanomeasuring machine (NMM-1) having a resolution of 0.1 nm over the positioning and measuring range of 25 × 25 × 5 mm is explained. Various developed probe systems have been integrated into the NMM-1 machine, including a focus sensor, a white light sensor, and tactile nanoprobes. Single-beam, double-beam, and triple-beam interferometers are installed into the NMM-1 machine to measure and control the six degrees of freedom. Measured results are presented.     

A novel parallel-kinematics mechanisms for integrated, multi-axis nanopositioning: Part 1. Kinematics and design for fabrication

Multi-axis micro and nanopositioning systems are increasingly used in much of the metrology and process equipment related to the field of nanotechnology. This, the first of a two-part series of papers on a novel piezo-driven, parallel-kinematics XYZ nanopositioning (PKXYZNP) stage, concentrates on the development of a viable scheme to achieve pure spatial translation. First, the mechanism is shown to admit closed-form solutions to both; the forward and reverse kinematic problems. The Jacobian and the dynamics of the system indicate that the mechanical structure produces a relatively large work volume, and is capable of high bandwidth and uniform performance across it. The fabrication of the system is described along with some basic testing of its Jacobian and its modal frequencies. Using capacitive gages, the stage is capable of about 85 μm of motion along each axis with a resolution of about 2–4 nm. The controls, testing and performance are discussed in detail in the companion paper [Dong J, Yao Q, Ferreira PM. A novel parallel-kinematics mechanism for integrated, multi-axis nanopositioning. Part 2. Dynamics, control and performance analysis. Precis Eng].     

A novel approach for mitigating the effects of pre-rolling/pre-sliding friction on the settling time of rolling bearing nanopositioning stages using high frequency vibration

Nanopositioning stages are used for ultra-precise positioning in many different applications. Among the bearing options available for long-range nanopositioning stages, rolling bearings are the most cost effective. However, rolling bearing nanopositioning (RB-NP) stages are well known to take a long time to reach their target positions in point-to-point positioning tasks due to pre-rolling/pre-sliding friction. This paper presents vibration assisted nanopositioning (VAN) – a novel approach for reducing the settling time of RB-NP stages using high frequency vibration (aka dither). VAN synergistically combines the electromechanical design and control of RB-NP stages to mitigate pre-rolling/pre-sliding friction using dither, without jeopardizing positioning precision. It is shown in simulations to exhibit superior positioning performance and robustness compared to model-based friction compensation methods. Experiments carried out on a prototype stage incorporating the VAN approach show a 52% reduction of mean settling time, based on 50 trials, when compared to a case without VAN. Moreover, the heat and potential wear induced by dither are shown to be practically insignificant.     

Preload characteristics identification of the piezoelectric-actuated 1-DOF compliant nanopositioning platform

Packaged piezoelectric ceramic actuators (PPCAs) and compliant mechanisms are attractive for nanopositioning and nanomanipulation due to their ultra-high precision. The way to create and keep a proper and steady connection between both ends of the PPCA and the compliant mechanism is an essential step to achieve such a high accuracy. The connection status affects the initial position of the terminal moving plate, the positioning accuracy and the dynamic performance of the nanopositioning platform, especially during a long-time or high-frequency positioning procedure. This paper presents a novel external preload mechanism and tests it in a 1-degree of freedom (1-DOF) compliant nanopositioning platform. The 1-DOF platform utilizes a parallelogram guiding mechanism and a parallelogram load mechanism to provide a more accurate actual input displacement and output displacement. The simulation results verify the proposed stiffness model and dynamic model of the platform. The values of the preload displacement, actual input displacement and output displacement can be measured by three capacitive sensors during the whole positioning procedure. The test results show the preload characteristics vary with different types or control modes of the PPCA. Some fitting formulas are derived to describe the preload displacement, actual input displacement and output displacement using the nominal elongation signal of the PPCA. With the identification of the preload characteristics, the actual and comprehensive output characteristics of the PPCA can be obtained by the strain gauge sensor (SGS) embedded in the PPCA.     

纳米X－Y工作台固有频率特性的研究

从理论和实验西方面对纳米ｘ—ｙ工作台的固有频率特性进行了分析计算和讨论。     

纳米X－Y工作台固有频率特性的研究

从理论和实验西方面对纳米x-y工作台的固有频率特性进行了分析计算和讨论。     

Large range nanopositioning stage design: A three-layer and two-stage platform

In this article, a novel two-dimensional nanopositioning platform (NanoPla) design is described. Its requirements are not only sub-micrometer accuracy for nanotechnology applications, but also long working range (XY-motion 50 mm × 50 mm). These features increase the common range operation of devices for nanotechnology issues (e.g. an atomic force microscope), and the number of potential metrological applications: positioning for manufacturing, manipulation or sample characterization. This novel design is characterized by a three-layer architecture and a two-stage motion strategy, which minimizes the measurement error. The manufactured prototype is here justified considering precision engineering principles and a wide state-of-art study of the literature, regarding long range nanopositioning stages. The simulations, the experimental results and the error budget also allowed, first, the optimization and, secondly, the validation of the design at nanometer scale.     

Simultaneous sensing and actuation with a piezoelectric tube scanner

Piezoelectric tube scanners with quartered external electrodes are the most widely used nanopositioning technology in modern scanning probe microscopes. There has been increasing interest in utilizing feedback control techniques to improve bandwidth and accuracy of these nanopositioners. The use of feedback requires a sensor to be incorporated into the nanopositioning device. Noncontact displacement sensors, e.g., capacitive and inductive sensors, have been used for this purpose. However, their measurements contain a significant noise component if operated over large bandwidths. The piezoelectric voltage induced in a tube nanopositioner has been proposed recently as an alternative measure of displacement with a much improved noise figure, up to three orders of magnitude better than capacitive sensors. In this arrangement, an electrode is used to actuate the tube, while the opposite electrode is used as a sensor. This approach has two drawbacks: (i) the operating range of the tube is reduced to half and (ii) the tube is not driven symmetrically, thus the opposite sides of the tube experience asymmetric stresses, i.e., in this mode of operation, the scanner is not a perfectly collocated system. In this paper, we present a new electrode pattern for piezoelectric tube scanners which addresses the above problems and allows simultaneous sensing and actuation of the tube in an efficient way.