微纳材料修饰的硅基微穿孔板共振降噪复合器件

探索了一种通过MEMS技术制备硅基微穿孔板共振降噪结构,并进一步将ZnO微米纳米材料加入其中以提高吸声性能的新方法．采用MEMS技术在硅片上得到了孔径为100μm、一致性良好的微孔阵列,将其与刚性底座组合在一起,构成硅基微穿孔板降噪器件．将通过水热合成法得到的ZnO微米纳米材料制备在后底板硅片上,并与硅基微穿孔板组装在一起,构成微米纳米复合降噪器件．对上述两种器件进行降噪实验,结果显示采用MEMS精密加工技术能够获得吸声系数较高的共振降噪器件,而经过ZnO微米纳米材料修饰后的复合器件,其在1500～6000Hz频段内的平均吸声系数提高了2．54％,达到85．87％．这一现象在1500～3000Hz频段尤为明显．因而,采用ZnO微米纳米材料修饰后的复合器件,吸声性能有所提升．     

基于激光捕捉微粒子实现微细加工的新概念研究

利用高倍显微物镜所聚合的激光在粒子表面所产生的辐射压可捕捉几个微米大小的高强度粒子,这些被捕捉的粒子在激光驱动下,能移动、转动及振动,可成为微加工工具,在被加工表面上形成微米乃至纳米级的表面微细切削。基于几何光学模型对捕捉进行数字仿真,所设计形状粒子的加工力最大可达到mW/N101.210-。     

人发的无机复制及金纳米粒子的原位合成

以人发为生物模板，用溶胶-凝胶法对人发的表皮结构进行了复制．其中以TEOS和水玻璃为前驱体时头发结构未得到复制，而以钛酸四丁酯为前驱体，得到二氧化钛微米管，微米管的外壁由屋顶瓦状排列的多孔二氧化钛层片组成，类似于头发表皮层结构．微米管上的纳米孔可以作为纳米反应器原位合成金属纳米粒子．微米管道、纳米孔与贵金属纳米粒子在这个体系中结合起来，因此在催化、吸附与分离等领域可能具有潜在的应用前景．     

软刻蚀技术及其应用

软刻蚀是通过表面带图案的弹性模板来实现图案的转移的图形复制技术，作为非光刻微米和纳米量级微加工方法，加工的分辨率可以达到5nm～100μm，它克服了传统光刻技术的缺陷，为形成和制作平面和曲面上的微米和纳米图案提供了简便、有效的低成本途径。本文将主要介绍微接触印刷、近场光刻蚀、纳米压印等软刻蚀方法的原理、方法以及面临的问题，并简介了它们在微米和纳米加工、微电子学、材料科学、光学、微电子机械系统、表面化学等方面应用。     

基于X光光刻的亚波长光栅

描述了一种新的亚波长光栅的微细加工技术，即X光光刻得到相应的亚微米级的线宽图形，再利用显影技术获得了高深宽比的立体亚波长光栅．用此纳米加工技术获得了栅距为500nm、250nm、150nm，光栅高度为1900nm的特殊纳米光栅模具，开发了纳米无反射结构，并研制成功了亚波长光栅．该亚微米线宽微细加工技术可用于布拉格光栅、DVD读写头、无反射表面等需要亚微米结构的器件中．     

表面强化技术

日本新和工业公司最近开发成功了利用喷镀陶瓷的金属零件表面强化技术,该公司采用独创的控制装置,使等离子喷镀机工作,对零件涂敷陶瓷粉末,使表面形成薄膜,大辐度地提高了零件的耐磨损性和耐热性。该表面强化技术首先是对加工零件的表面进行喷射处理,使表面略带凹凸。然后以能够喷射出约20,000℃氩焰的喷镀机,强制性地喷镀陶瓷粉末,使之形成厚度为100—150微米的膜     

表面改性纳米氧化钛的强电流变效应

以十二烷基硫酸钠（SDS）为表面改性剂，用溶胶凝胶方法制备出无定型改性纳米氧化钛颗粒，平均粒径为100nm．颗粒表面改性极大地提高了纳米氧化钛与硅油的浸润性和所配制电流变液的力学性能．颗粒浓度为3．0g／ml时，材料显示最佳的电流变效应，其挣态剪切应力值可达130kPa（4kV／mm直流电场）．与微米电流变液比较，纳米电流变液的抗沉降性能有较大的改善．颗粒的纳米粒径尺度、与基液良好的润湿性是形成改性纳米颗粒强电流变效应的主要原因．     

纳米技术的国际现状

工业和科技的发展使机械加工及测量的准确度进入了纳米（十亿分之一米，urn）星级的范围。例如：单模光纤的连接，要求轴向误差为一微米的几分之一即百纳米量级；半导体硅片上器件尺寸为几十纳米；金刚石加工、弹性发射加工则要求光滑度（表面形状、波纹、粗糙度等）在纳米的水平。这些制造的尺寸和公差在0．Inm至100urn范围的技术，称为纳米技术（nanotechnology）。英国自60年代就开始了纳米技术的研究工作，英国1986年在国家物理研究所（NPL）建立了国家纳米技术研究所，并投入研究经费1500万英镑。目前一些发达国家都非常重视对纳米技…     

纯钛基体长效超疏水表面的低成本制备

为降低钛基上超疏水表面的制备成本,提高超疏水表面的耐久性能,以喷砂-阳极氧化法在纯钛基体上构造微纳复合粗糙结构,并使用商用氟碳罩光漆直接对其进行修饰获得超疏水性表面。利用傅里叶变换红外光谱(FTIR),场发射扫描电子显微镜(FE-SEM)和接触角测试等技术对超疏水性表面的化学组成、表面形貌、润湿性和表面耐久性进行了研究。结果表明:喷砂处理在钛基表面构筑微米级凹坑,阳极氧化通过形成网状氧化膜在钛基表面构造纳米级结构,氟碳罩光漆修饰该微纳复合粗糙表面后,为表面引入大量含氟基团,使其获得超疏水性能。超疏水性表面与纯水的静态接触角达162°±2.3°,滚动角为2.1°±0.2°,具有优异的环境耐久性。     

基于MEMS技术集成硅微棱镜耦合和微流道的近红外表面等离子体谐振芯片

为促进表面等离子体谐振（surface plasmon resonance, SPR）测试技术在片上的实现，提出硅基近红外SPR芯片，由硅微棱镜、金属膜和聚合物微流体通道组成．利用有掩膜和无掩膜各向异性湿法腐蚀加工出底角为25．24。的单微硅棱镜阵列，用有掩膜各向异性湿法腐蚀加工出底角为54．74。的双微硅棱镜阵列，利用聚合物的复制注塑技术加工得到微流体通道．在波长1550nm时进行仿真与实验测试，实验测得以空气、水和乙醇为测试介质的SPR角分别为16．75°、22．58°和22．72°，这些值比以玻璃棱镜加工SPR传感器测得的SPR角要小很多．通过实验表明，近红外SPR芯片可以实现表面等离子体谐振传感器微型化，进而推动微全分析系统的实现，降低其成本并提高其性能．     

Electroforming for replicating nanometer-level smooth surface

We proposed and developed a new electroforming process for the replication of surfaces having nanometer-level smoothness. In the electroforming process, the separation method plays an important role in preventing the degradation of the surface morphology. The key point in this process is the fabrication of a metal film as an electrode on the master surface. Cr atoms are deposited by an arc plasma deposition method and act as a binding material. Subsequently, a nickel film is fabricated by electron beam deposition to form an electrode. Electrodeposition is then carried out in a nickel sulfamate bath. By controlling the density of Cr atoms on the master surface, the binding strength between the nickel film and master surface can be adjusted, which makes it possible to separate the metal film from the master surface smoothly. As a result, a surface roughness of 0.22 nm (root mean square) has been achieved in a 64 microm x 48 microm area of a replicated surface.     

Electrochemically replicated smooth aluminum foils for anodic alumina nanochannel arrays

A fast electrochemical replication technique has been developed to fabricate large-scale ultra-smooth aluminum foils by exploiting readily available large-scale smooth silicon wafers as the masters. Since the adhesion of aluminum on silicon depends on the time of surface pretreatment in water, it is possible to either detach the replicated aluminum from the silicon master without damaging the replicated aluminum and master or integrate the aluminum film to the silicon substrate. Replicated ultra-smooth aluminum foils are used for the growth of both self-organized and lithographically guided long-range ordered arrays of anodic alumina nanochannels without any polishing pretreatment.     

Generation of large-diameter diffractive elements with laser pattern generation

We describe the design and construction of a high-precision laser writing machine for the direct generation of large-diameter rotationally symmetric diffractive optics with continuous profiles in photoresist. The photoresist profile can be used as a replication master surface or etched into a silica substrate. Machine design methodology, as well as qualification of performance, is provided. Test results for an f/2 100-mm clear-aperture diffractive lens directly etched into a silica substrate are presented. Diffraction efficiency as a function of zone spacing and wave-front performance are given.     

Nanomolding of PEG‐Based Hydrogels with Sub‐10‐nm Resolution

A simple, soft nanolithographic method is used to fabricate sub‐10‐nm structures on star polyethylene glycol‐based hydrogels and perfluoropolyether‐based materials. Very small features, for example, gold nanoparticles of size ≈8 nm with an interparticle distance of ≈100 nm, are successfully reproduced from a hard silicon master into both elastomers. Scanning force microscopy is used to investigate the replicas, and the original hexagonal pattern of the nanoparticles is clearly recognized. In addition, both replicas are usable as secondary, soft molds yielding positive copies of the primary, hard master. The results presented here show similar replication capabilities for both elastomers despite the markedly different properties of the precursors. Moreover, the hydrogel material can be easily peeled off from both soft and silicon masters without the need for surface treatment. The procedure allows nanopatterning of a biocompatible material over large areas, which is a useful tool to investigate cellular responses to defined nanotopography.     

Replication of a holographic ion-etched spherical blazed grating for use at extreme-ultraviolet wavelengths: topography

We have measured the topography of a holographic ion-etched spherical blazed grating and three of its replicas using an atomic force microscope. The master grating had a roughness of less than 5 angstroms rms, a blaze angle of 2.5 degrees, and an antiblaze angle of 3.3 degrees. Thus the groove profile was more triangular than sawtooth. We find that the replication process did not significantly change the master grating. Moreover, we find no significant difference in roughness, blaze angle, or antiblaze angle between the master and its replicas before or after multilayer coating. However, bumps were observed on the gratings after coating, the cause of which is not understood. Although widespread, they occupy a relatively small fraction of the total area.     

Reference-beam system for measuring relative small-surface local irregularities of a reflective object

We present an optical technique for measuring irregularities on a small local surface ( approximately lambda/100). This new technique uses a narrow laser beam as a local probe. The probe beam interferes with a reference beam. We use a 90 degrees phase delay on the reference beam to increase the sensitivity. We show that if the test surface vibrates laterally, the collected power of the interferogram encodes as amplitude modulations, on a sinusoidal temporal carrier, the local surface irregularities.     

FATIGUE BEHAVIOUR OF A RAIL STEEL UNDER LOW AND HIGH LOADING RATES

Abstract— In this study, both sinusoidal wave loading and rectangular pulse (impact) loading are applied to a sample of rail steel in order to compare the growth rates for a surface fatigue crack. The results show that the rectangular pulse (impact) loading gives a crack growth rate on average 5 times that of the sinusoidal wave loading but can be almost 100 times in some instances. There are distinct differences between the fractograph patterns under the two modes of loading. The fractograph under sinusoidal wave loading clearly exhibits the pearlite structure of the material but under impact loading this microstructure is not revealed; only a quasicleavage pattern is observed. Analysis of the experimental fatigue crack growth data indicated that the surface fatigue crack growth rate behaviour could be described by the Paris-type relationship.     

Carbon nanofibers in a gradient-porous silicon structure

Silicon membranes with through pores have been manufactured based on silicon plates with a gradient-porous structure, in which the pore cross section and structure varies with depth. In order to increase the specific surface of membranes, a layer of carbon nanofibers and nanotubes has been formed on the surface of macropores in silicon. The obtained structure can serve as a basis for the development of electrodes for solid polymer fuel cells with a specific area of conducting surface (with respect to carbon) of no less than 100 m²/g.     

疏水植物表面微纳复合结构电铸模芯的制备

以竹叶下表面为疏水生物母板,针对疏水表面电铸成型的特殊性,分别采取湿润剂浸润处理和阴极水平旋转运动两个技术手段改善微纳复合结构的电铸成型质量。结果表明:浸润处理可有效提高沉积离子在微纳米凹槽内部的沉积,阴极水平旋转对提高电铸镍模芯宏观质量和微观结构复制质量均有一定效果。采用浸润处理与阴极旋转相结合的电铸复制工艺,可明显提高竹叶下表面微纳复合结构的复制质量,成功实现具有疏水植物表面微纳复合结构的模塑成型镍模芯的高质量制备。     

The influence of sublayer material on surface properties of electrodeposited nickel with periodical structures

Surface topography, hardness and microstructure of nickel coatings electrodeposited on Si master with a periodical structure have been studied depending on vacuum deposited sublayer material (Ni, Cu or Ag). It is shown that the quality of replication of silicon master in a nickel shim electrodeposited simultaneously on different sublayers is dependent on the material used. All types of the analyzed coatings enabled transfer of lateral dimensions and showed good replication quality of the tested periodical structures (2 μm period), while the structure replicated using the coatings deposited on the Ni sublayer exhibited the worst roughness. The hardness of the electrodeposited layers was found to be dependent on the sublayer material used as well as on the side of deposit. Despite the fact that the backside of nickel shim had the same hardness for all the sublayers used, it was found that the hardness of the working surface with periodical structure (the side that has been in contact with the vacuum deposited layer) is dependent on the sublayer material: the Ni and Cu sublayers increased the hardness of Ni coating, while for the nickel shim deposited on Ag sublayer the hardness was reduced.