Nano-Hardness Tester and its Application in MEMS

微机电系统(MEMS)技术的迅速崛起,推动了对其所用材料和结构的力学性能研究。简要介绍纳米硬度技术的发展展、理论模型和MTS公司的Nano Indenter XP系统的配置、测量原理及功能。并根据我们的一些研究结果,说明它在微机电系统中的应用。

A moving-coil designed micro-mechanics tester with application on MEMS

A moving-coil designed micro-mechanics tester, named as MicroUTM (universal testing machine), is in-house developed in this paper for micro-mechanics tests. The main component is a moving coil suspended in a uniform magnetic field through a set of springs. When a current passes through the coil, the electromagnetic force is proportional to the magnitude of the current, so the load can easily be measured by the current. The displacement is measured using a capacitive sensor. The load is calibrated using a Sartorius BP211D analytical balance, with a resolution/range of 0.01 mg/80 g or 0.1 mg/210 g. The displacement is calibrated using a HEIDENHAIN CT-6002 length gauge with an accuracy of +/- 0.1 mu m. The calibration results show that the load range is +/- 1 N and the displacement range is +/- 300 mu m. The noise levels of the load and displacement are 50 mu N and 150 nm, respectively. The nonlinearity of the load is only 0.2%. Several in-plane load tests of the MEMS micro-cantilever are performed using this tester. Experimental results, with excellent repeatability, demonstrate the reliability of the load measurement as well as the flexible function of this tester.

Design and construction of a static tester for blue ray optical storage

Blue ray optical storage is one of the important trends in the area of information storage, and attracts a number of researchers. Static tester for blue ray optical storage plays an important role in storage media research. We designed and constructed a static tester, in which modularization makes it very convenient to expand function. Employment of modulation/demodulation technique weakens test error so as to increase test precision. Focus move mode and the nano-positioners facilitate the relocation of recording marks. Only one laser with wavelength 406.7 nm is used. In this paper, system design and characteristics are represented in detail, and some experimental results are also given to show that the static tester can perform successfully, acting as research platform for blue ray optical storage. (c) 2005 Elsevier GmbH. All rights reserved.

The mechanical properties of an aluminum alloy by plasma-based ion implantation and solution-aging treatment

The age-strengthening 2024 aluminum alloy was modified by a combination of plasma-based ion implantation (PBII) and solution-aging treatments. The depth profiles of the implanted layer were investigated by X-ray photoelectron spectroscopy (XPS). The structure was studied by glancing angle X-ray diffraction (GXRD). The variation of microhardness with the indenting depth was measured by a nanoindenter. The wear test was carried on with a pin-on-disk wear tester. The results revealed that when the aluminum alloys were implanted with nitrogen at the solution temperature, then quenched in the vacuum chamber followed by an artificial aging treatment for an appropriate time, the amount of AIN precipitates by the combined treatment were more than that of the specimen implanted at ambient temperature. Optimum surface mechanical properties were obtained. The surface hardness was increased and the weight loss in a wear test decreased too.

(Ti,Al)N Film On Normalized T8 Carbon Tool Steel Prepared By Pulsed High Energy Density Plasma Technique

Under optimized operating parameters, a hard and wear resistant ( Ti,Al)N film is prepared on a normalized T8 carbon tool steel substrate by using pulsed high energy density plasma technique. Microstructure and composition of the film are analysed by x-ray diffraction, x-ray photoelectron spectroscopy, Auger electron spectroscopy and scanning electron microscopy. Hardness profile and tribological properties of the film are tested with nano-indenter and ring-on-ring wear tester, respectively. The tested results show that the microstructure of the film is dense and uniform and is mainly composed of ( Ti,Al)N and AlN hard phases. A wide transition interface exists between the film and the normalized T8 carbon tool steel substrate. Thickness of the film is about 1000 nm and mean hardness value of the film is about 26GPa. Under dry sliding wear test conditions, relative wear resistance of the ( Ti,Al)N film is approximately 9 times higher than that of the hardened T8 carbon tool steel reference sample. Meanwhile, the ( Ti,Al)N film has low and stable friction coefficient compared with the hardened T8 carbon tool steel reference sample.

Characteristics of the interface of a laser-quenched steel substrate and chromium electroplate

The interface of a laser-discrete-quenched steel substrate and as-deposited chromium electroplate was investigated by ion beam etching, dissolving-substrate-away and using a Vickers microhardness tester, in an attempt to reveal the mechanism that the service life of the chromium-coated parts is increased by the duplex technique of laser pre-quenching plus chromium post-depositing. The laser quenching of the steel substrate can reduce the steep hardness gradient at the substrate/chromium interface and improve the load-bearing capacity of chromium electroplate. Moreover, the laser quenching prior to plating has an extremely great effect on the morphologies and microstructure of the substrate/chromium interface: there is a transient interlayer at the original substrate/chromium interface while there is not at the laser-quenchedzone/chromium interface; the near-substrate surface microstructure and morphologies of the free-standing chromium electrodeposits, whose substrate was dissolved away with nital 30% in volume, inherit the periodically gradient characteristics of the laser-discrete-quenched substrate surface. (c) 2006 Elsevier B.V. All rights reserved.

Tensile and compressive deformation of a short-glass-fiber-reinforced liquid-crystalline polymer

Results of tensile and compression tests on a short-glass-fiber-reinforced thermotropic liquid crystalline polymer are presented. The effect of strain rate on the compression stress-strain characteristics has been investigated over a wide range of strain rates epsilon between 10(-4) and 350 s-1. The low-strain-rate tests were conducted using a screw-driven universal tensile tester, while the high-strain-rate tests were carried out using the split Hopkinson pressure bar technique. The compression modulus was shown to vary with log10 (epsilon) in a bilinear manner. The compression modulus is insensitive to strain rate in the low-strain-rate regime (epsilon = 10(-4) - 10(-2) s-1), but it increases more rapidly with epsilon at higher epsilon. The compression strength changes linearly with log10 (epsilon) over the entire strain-rate range. The fracture surfaces were examined by scanning electron microscopy.

纳米压痕仪接触投影面积标定方法的研究

基于Oliver与Pharr方法的纳米压痕实验以其简单方便获得广泛的应用,但众多因素对压痕实验结果的影响范围并无明确的结论.其中压痕接触面积的确定是一个重要环节,该因素对实验结果,特别是小深度下的实验结果具有重要影响.仔细分析了Oliver与Pharr方法并进行了几种材料的纳米压痕实验,针对该方法在接触深度确定、不同深度范围下方法的适用性进行了说明.分析结果表明,对所有的材料使用统一的面积公式,只有在大压痕深度时才是适用的,而在小压痕深度时可能带来较大的误差.因此,应慎重使用由Oliver与Pharr方法得到的小压痕深度的硬度数据.

模块化蓝光光存储性能静态测试系统

蓝光光存储是信息存储领域发展的一个重要方向。测试系统是研究蓝光光存储材料的必备条件，为建立蓝光光存储研究平台，设计和搭建了一套模块化蓝光光存储性能静态测试系统。激光工作波长为406．7nm。系统采用调制解调技术降低系统噪声，提高测量粘度：采用光点移动模式降低对样品尺寸的要求；采用纳米平台提高记录点的反复定位性能。实验结果证明测试系统性能良好，可以满足蓝光光存储性能静态测试要求。

PEFCSH 的建立及在基因组特异序列克隆上的应用

基因组特异序列是跟踪外源染色质、鉴定易位系的特异探针。本文介绍一种带反馈控制的PCR增效减法杂交（PEFCSH），证明可高效克隆基因组特异序列。 带PCR接头的黑麦DNA片段与固定化的小麦ssDNA杂交，同源的片段将被吸附。用PCR扩增吸附的DNA，可监测杂交液中与小麦同源的DNA，确定是否还要再杂交。5轮连续杂交后，杂交液中的DNA几乎全为黑麦特异DNA，纯化后，用PCR扩增到方便操作的数量。经检测，PEFCSH片段99%为黑麦基因组特异性序列，富集度超过230倍。 PEFCSH片段克隆后检测：插入片段在120bp～2000bp，峰值250bp左右;306个克隆中301个显黑麦特异性，表明了PEFCSH的高效性。Tomita等曾用普通减法杂交富集黑麦特异序列，所得克隆只有6.3%为黑麦特异。 与数据库对比，分离片段有的为新序列，更多的与已知的黑麦特异重复序列同源。用其中一条作探针进行Southern杂交，小麦不显带，黑麦显阶梯型带，说明它是特异性串联重复序列。 PEFCSH有如下特点：1. 实时监测杂交液中非特异DNA，首次引入反馈控制，确保杂交达到预期效果。2. 用PCR制备Tester只需少量样品就可以分离特异序列。3. 采用固相减法杂交，大大简化Test与Driver的分离。4. 用PCR克服常规减法杂交操作性差的弱点。5. 富集特异单链和双链DNA，减少特异序列丢失。6. 适用于大多数分离两组相关核酸中的差异成分。

银额果蝇B染色体特异性基因的初步研究

采用代表性差异分析法(RDA)研究了银额果蝇两个单雌系AKM46(含B染色体)和AGZ2(不含B染色体)两基因组间的差异。用AKM46作检测(tester)扩增子,AGZ2作驱赶(driver)扩增子,通过三轮消减杂交后,获得了6个差异片段(100bp-300bp)。实验证实了其中两个片段来自含有B染色体的单雌系AKM46,而且可能是B染色体上的特异基因片段。

鲫鱼低氧相关基因差减cDNA文库的构建与分析

鲫鱼对低氧具有极强的耐受性。在低氧状态下鲫鱼鳃瓣表面积增加,无氧代谢增强,能量消耗降低。但是人们对鲫鱼产生这些低氧反应的分子机理还缺乏了解。本研究以1%低氧处理24h的鲫鱼囊胚细胞(CAB)作为检测子(Tester),常氧条件下培养的CAB细胞作为驱赶子(Driver),分别提取总RNA,利用SMART cDNA技术合成双链cDNA,经差减杂交和抑制性PCR扩增获得差减PCR产物。然后将差减PCR产物连接到pGEM-T载体上,构建差减cDNA文库。以管家基因β-actin作为指标检测差减效率,发现该文库差

Effect of incorporating nonlanthanoidal indium on optical properties of ferroelectric Bi4Ti3O12 thin films

Bi4Ti3O12 (BTO) and Bi3.25In0.75Ti3O12 (BTO:In) thin films were prepared on fused quartz and LaNiO3/Si (LNO) substrates by chemical solution deposition (CSD). Their microstructures, ferroelectric and optical properties were investigated by X-ray diffraction, scanning electron microscope, ferroelectric tester and UV-visible-NIR spectrophotometer, respectively. The optical band-gaps of the films were found to be 3.64 and 3.45 eV for the BTO and BTO:In films, respectively. Optical constants (refractive indexes and extinction coefficients) were determined from the optical transmittance spectra using the envelope method. Following the single electronic oscillator model, the single oscillator energy E-0, the dispersion energy E-d, the average interband oscillator wavelength lambda(0), the average oscillator strength S-0, the refractive index dispersion parameter (E-0/S-0), the chemical bonding quantity beta, and the long wavelength refractive index n(infinity) were obtained and analyzed. Both the refractive index and extinction coefficient of the BTO:In films are smaller than those of the BTO films. Furthermore, the refractive index dispersion parameter (E-0/S-0) increases and the chemical bonding quantity beta decreases in the BTO and BTO:In films compared with those of bulk. (C) 2007 Published by Elsevier B.V.

Study on mechanical properties of GaN epitaxy films grown on sapphire by MOCVD

GaN epitaxy films were grown on (0001) oriented sapphire substrate by metal-organic vapor deposition(MOCVD). AFM and SEM were used to analyze the surface morphology of GaN films. Hardness and critical load of GaN films were measured by an nano-indentation tester, friction coefficient by reciprocating UMT-2MT tribometer. It is found that the surface of GaN film is smooth and the epitaxial growth mechanism is in two-dimension mode, GaN epitaxy films also belong to ultra-hardness materials, whose hardness is 22.1 MPa and elastic modulus is 299.5 GPa. Adhesion strength of epitaxial GaN to sapphire is high, and critical load reaches 1.6 N. Friction coefficient against GCr15 ball is steadily close to 0.13, while GaN films turns to be broken rapidly by using Si3N4 ceramic ball as counterpart.

Parallel optical communication subsystem based on VCSEL - art. no. 67833I

A parallel optical communication subsystem based on a 12 channels parallel optical transmitter module and a 12 channels parallel optical receiver module can be used as a 10Gbps STM-64 or an OC-192 optical transponder. The bit error rate of this parallel optical communication subsystem is about 0 under the test by SDH optical transport tester during three hours and eighteen minutes.