基于超纯水电化学加工的扫描直写技术

为了充分发挥电化学加工以离子状态去除材料的加工机理,实现其在微细、精密,甚至是纳米加工领域中的应用,针对绿色制造和微细加工的需求,提出以超纯水为电解液的微细电化学加工方法．采用阳离子交换膜促进超纯水解离,提高电化学加工过程中电流密度;利用微探针作为工具电极,通过数控机床控制运动轨迹保持与阳极表面的间距恒定,以不同路径横向扫描工件,即可在工件阳极表面加工出2D／3D几何结构．并通过试验加工字母“PW-ECM”,验证了超纯水作为电解液进行电化学扫描直写加工技术的可行性．     

基于多功能加工平台的微细电解加工

电解加工在加工过程中因难以控制加工形状而很少应用在微细加工领域,为了对微细电解加工可行性进行探索,设计了多功能微细加工平台,利用多功能微细加工平台可为微细电解加工在线制作电极,采用低加工电压、低浓度的钝化电解液、高频窄脉冲电源和高速旋转的微细电极,进行了微细电解加工实验,取得了很好的工艺效果,加工间隙是影响加工精度的关键因素,设计了一个加工间隙控制伺服系统,以保证微小的加工间隙,在厚为100μm的不锈钢薄片上用微细电解打孔加工出直径为65μm的微小孔,利用微细电解加工时电极无损耗,提出采用简单圆柱微细电极进行微细电解铣削,加工出较高精度的微结构,取得了较好的工艺效果,从而验证了该微细电解加工装置的微细加工能力和方法的可行性。     

基于双电层电容的微细电解加工间隙的在线检测

根据微细电解加工中工具电极下端面面积远小于工件表面的非对称特征,在水基中性盐钝性电解液侧流冲入和金属电极处于钝化状态的条件下,提出了一种基于双电层电容的微细电解加工间隙的在线检测方法．在微细工具电极和／或工件上不外加传感器的前提下,利用工具电彬溶液界面上双电层电容值随加工间隙增大而单调递增的变化关系,精确、快速地实现加工间隙的在线检测．在冲液速度为1．058m／s的条件下,当加工间隙在O．100μm时,可在数毫秒内在线检测出微细电解加工间隙的大小,数值仿真与实验测量值之间的最大相对误差小于10％．为实现高精度、高质量、稳定的微细电解加工提供必要条件．     

采用疏水材料侧壁绝缘电极的微细电解加工实验

微细电解加工中工具电极和工件之间的加工间隙是影响加工效果的核心因素.工具电极侧壁施加绝缘膜的工艺方法,可显著改变侧面加工间隙内的电场分布,提高加工精度,同时保持原有的加工效率,有着良好的应用前景.本文基于仿真方法,分析了绝缘膜对端面加工间隙和侧面加工间隙的影响规律,研究了绝缘膜疏水性质对电解加工中产生的氢气泡运动的吸附作用对微细电解加工的影响.在直径为数十到数百微米的钨丝侧壁制备出可用于微细电解加工的几微米厚的硅胶疏水材料侧壁绝缘薄膜.在硝酸钠电解液中,实现了不锈钢材料上将微气泡附着于电极前端与绝缘膜结合处、保护绝缘膜和约束杂散腐蚀的微细电解端面分层扫描加工效果.     

LIGA技术及其应用

简要介绍了近几年发展起来的一种能进行三维微细加工的新技术－－ＬＩＧＡ技术。它由Ｘ光深层光刻。微电铸和微塑铸组成，其特点是获得的微器件具有较大的深宽比，厚度可达几百微米，并且侧壁陡峭，表面平整，用此技术可加工由高分子材料，各种金属和陶瓷组成的微器件。     

微细槽的电化学铣削加工

为了研究不锈钢微细槽的电化学铣削加工技术,使用微细的、旋转的圆柱电极作为电化学加工的阴极,采用脉冲电压电化学加工技术用类似铣削加工的方法加工微细槽.研究了脉冲宽度对电极和微细槽侧面加工间隙的影响,并对微细槽铣削加工过程中的电场和流场进行了分析.在相同的电压幅值和平均电压条件下,脉冲宽度越大,侧面加工间隙越大.电场和流场分析表明,微细槽的侧面加工间隙和侧面倾斜度随着脉冲宽度的减小以及进给速度的增加而减小.当脉冲宽度小于工件表面双电层充电时间常数时,采用钝化电解液能够减小电化学杂散腐蚀和微细槽的侧面倾斜度.当脉冲宽度为0.4μs、进给速度为24μm/min时,微细槽的侧面倾斜度很小,侧面加工间隙达到10μm.实验结果表明,采用超短脉冲电化学铣削加工方法和合适的电解液,能够提高微细槽的加工精度.     

飞秒激光双光子微细并行加工方法

飞秒激光三维微细加工技术具有真三维的制作能力和亚微米的加工分辨率等特点,因此获得越来越多的关注,但其串行工艺加工效率低是其技术难点．为了提高加工效率,搭建了一套飞秒激光并行加工平台,利用微透镜阵列实现飞秒激光分束聚焦,初步实现了双光子微细并行加工,在光敏树脂和玻璃上分别并行加工出多个二维结构,加工单点分辨率达到1．25μm．针对实验结果,对实验的加工一致性和分辨率进行分析,提出了进一步提高加工效率和加工一致性的方法．     

一种三维金属微型腔的组合加工方法

为了制作局部为三维结构的金属模具微型腔,实验研究了一种组合加工新工艺,即先用紫外线光刻和电铸成形（准LIGA）技术在模具基底上制作二维金属微型腔,再用微细电火花成形加工（EDM）技术对微型腔的局部进行修形,得到局部为三维结构的微型腔,电火花修形的位置根据微型腔结构的设计要求而定．以制作聚合物微流控芯片用的金属模具为试件,以微细电火花成形加工中影响工件表面粗糙度的因素分析为理论指导,应用该方法制作了局部侧壁倾斜的三维微型腔．根据测量结果,两边侧壁与水平方向的夹角分别为49．6°和46．4°,倾斜侧壁的表面粗糙度Rs为0．391μm．     

电解转印表面织构的定域性研究

研究表明,摩擦副表面织构可以有效地改善表面摩擦学性能.电解转印工艺是加工摩擦副表面织构的有效途径.以加工阵列微坑为例.从电解转印的定域性角度出发,提出了以微坑腐蚀系数作为电解转印定域性的评价指标.根据电场理论,建立了电解转印过程阴阳极间电场理论模型,采用有限元电场分析方法探讨阴阳极间距对电解转印过程中阳极表面电场分布的影响.构建电解转印表面织构试验平台,通过试验研究考察了阴阳极间距和电解加工电压对微坑形貌和腐蚀系数的影响.试验结果表明,阴阳极间距由20岬增加到100 μm时,微坑直径由55μm增加到130 μm,微坑腐蚀系数由3减小到0.012 5,电解转印的定域性降低.加工电压对电解转印定域性有一定的影响,当其他参数不变,加工电压增加到20 V时,微坑腐蚀系数略有下降,微坑轮廓较为清晰.     

高性能微细电铸的实验研究

将纳米稀土La2O3作为添加剂,研究其在微细电铸镍工艺过程中的影响.采用SEM等现代分析手段对微细铸层微观结构和性能进行了测试.结果表明:纳米La2O3能够在阴极沉积表面发生特性吸附,具有增大阴极极化,细化微细电铸层晶粒,获得的微细铸层的显微硬度和耐磨性等力学性能比普通电铸层有大幅度的提高.     

Fabrication of magnetic nanodot arrays for patterned magnetic recording media

Fabrication processes of arrayed magnetic nanodots for the use of patterned magnetic recording media were reviewed. One candidate for the patterned media is ordered assemble of magnetic nanoparticles, and the other is patterned magnetic thin films fabricated using various micro/nano scale machining processes. For the formation of patterned masks and molds, lithography processes as well as self-organized pattern formation are utilized. For the deposition processes of magnetic dots, electrochemical deposition processes were widely used. These fabrication processes are reviewed mainly from recent reports. The recording systems for the patterned media including probe-type-recording are also overviewed.     

石墨的微加工工艺研究

石墨具有固态超滑和耐酸、耐碱和耐有机溶剂腐蚀等特性, 使其有望成为微机电系统 (MEMS) 基础材料的一种选择。如能通过微纳米加工工艺对石墨进行微加工并在石墨上大批量、稳定、可控地制备各种掩模图案和石墨微结构, 一定程度上可以推动石墨成为MEMS基础材料。故本文通过工艺设计和参数摸索, 利用薄膜沉积、光刻、刻蚀等常用的微纳米加工工艺对石墨进行微加工研究, 并对加工后的石墨进行表征。结果表明, 利用薄膜沉积技术在石墨表面沉积的薄膜可以满足后续光刻和刻蚀等工艺的要求。同时, 采用光刻技术能在石墨表面大批量、稳定、可控地加工出不同形状, 不同尺寸的光刻胶掩模图案。此外, 利用刻蚀技术可以在石墨上大批量、稳定、可控地加工出形状较规则, 排列整齐且垂直度较高的石墨微结构。     

Review: Developments in micro/nanoscale fabrication by focused ion beams

Focused ion beam (FIB) technology has become increasingly attractive for the fabrication of micro/nano structures for the purpose of the demands in industry and research. In this paper, various efforts to fabricate micro/nanoscale structure and geometrically complex structure are described, and their efficiency and structural stability are discussed. In order to fabricate such complex structures with micro/nanoscale features, the capability of the FIB is directly related to its destructive and constructive processes. It can also be used for modification and imaging in four basic modes. The fabrication processes, including both milling and deposition, are related to the precision fabrication of samples at the micro/nanoscale. By taking into account material processing rates, surface morphologies with nanoscale effects can be explained in detail. Finally, very recent developments using FIB will be reviewed.     

Advanced Carbon for Flexible and Wearable Electronics

Flexible and wearable electronics are attracting wide attention due to their potential applications in wearable human health monitoring and care systems. Carbon materials have combined superiorities such as good electrical conductivity, intrinsic and structural flexibility, light weight, high chemical and thermal stability, ease of chemical functionalization, as well as potential mass production, enabling them to be promising candidate materials for flexible and wearable electronics. Consequently, great efforts are devoted to the controlled fabrication of carbon materials with rationally designed structures for applications in next‐generation electronics. Herein, the latest advances in the rational design and controlled fabrication of carbon materials toward applications in flexible and wearable electronics are reviewed. Various carbon materials (carbon nanotubes, graphene, natural‐biomaterial‐derived carbon, etc.) with controlled micro/nanostructures and designed macroscopic morphologies for high‐performance flexible electronics are introduced. The fabrication strategies, working mechanism, performance, and applications of carbon‐based flexible devices are reviewed and discussed, including strain/pressure sensors, temperature/humidity sensors, electrochemical sensors, flexible conductive electrodes/wires, and flexible power devices. Furthermore, the integration of multiple devices toward multifunctional wearable systems is briefly reviewed. Finally, the existing challenges and future opportunities in this field are summarized.     

多孔网络结构玻璃材料的制备及其应用研究

主要介绍了高硅氧多孔网络结构玻璃光学基片、微珠和多孔光纤的制备方法及其在特种物质分离、负载、光学传统以及进行纳米复合制备新的光电材料等方面的应用研究情况，并分析了其技术发展和应用前景。     

Discovering Reactant Supply Pathways at Electrode/PEM Reaction Interfaces Via a Tailored Interface-Visible Characterization Cell

In situ and micro-scale visualization of electrochemical reactions and multiphase transports on the interface of porous transport electrode (PTE) materials and solid polymer electrolyte (SPE) has been one of the greatest challenges for electrochemical energy conversion devices, such as proton exchange membrane electrolyzer cells (PEMECs), CO₂ reduction electrolyzers, PEM fuel cells, etc. Here, an interface-visible characterization cell (IV-CC) is developed to in situ visualize micro-scaled and rapid electrochemical reactions and transports in PTE/SPE interfaces. Taking the PEMEC of a green hydrogen generator as a study case, the unanticipated local gas blockage, micro water droplets, and their evolution processes are successfully visualized on PTE/PEM interfaces in a practical PEMEC device, indicating the existence of unconventional reactant supply pathways in PEMs. Further comprehensive results reveal that PEM water supplies to reaction interfaces are significantly impacted with current densities. These results provide critical insights about the reaction interface optimization and mass transport enhancement in various electrochemical energy conversion devices.     

支撑光学制造的几何量计量技术(英文)

几何量计量技术大量应用于光学制造业以检测零件质量和控制生产过程,是光学制造业的核心技术,涉及微纳米结构的几何量计量以及平面、球面、非球面、直纹曲面及自由曲面的面形计量.本文综述了德国联邦物理技术研究院支撑光学制造的部分计量技术.介绍了一种测量范围为25 mm×25 mm×5 mm的计量型大范围原子力显微镜(AFM),可灵活多样地测量各种微纳结构.介绍了一种新颖的AFM探针(ACP),可实现微纳结构侧壁形貌的直接、无损测量.介绍了一种应用Flared AFM探针的真三维AFM及其用于减少针尖磨损的矢量探测技术,可应用于各种纳米结构的真三维测量.介绍了可用于平面和中等曲面面形绝对测量的两种方法:差分型激光束偏转法和可溯源多路传感器法(TMS).讨论了面形测量中存在的挑战性难题.介绍了可用于面形测量的高精度三坐标测量机.     

自呼吸式微型直接甲醇燃料电池的设计与性能分析

为了提高燃料电池的机械强度并降低加工成本,设计了一种基于不锈钢材料的空气自呼吸式微型直接甲醇燃料电池(DMFC).采用高温微型冲压技术制作电池的极板,并在其表面溅射Au和TiN来防止电化学腐蚀和减少接触电阻.在不同运行参数条件下对电池进行性能和稳定性的测试,结果表明阳极流速、甲醇浓度以及工作温度等均对电池性能有较明显的影响.该自呼吸式微型直接甲醇燃料电池在室温(20℃)条件下最高功率密度达到23.38 mW/cm2,并在温度40℃时可稳定地长时间工作,具有一定的应用价值.     

Porous Graphene Materials for Advanced Electrochemical Energy Storage and Conversion Devices

Combining the advantages from both porous materials and graphene, porous graphene materials have attracted vast interests due to their large surface areas, unique porous structures, diversified compositions and excellent electronic conductivity. These unordinary features enable porous graphene materials to serve as key components in high‐performance electrochemical energy storage and conversion devices such as lithium ion batteries, supercapacitors, and fuel cells. This progress report summarizes the typical fabrication methods for porous graphene materials with micro‐, meso‐, and macro‐porous structures. The structure–property relationships of these materials and their application in advanced electrochemical devices are also discussed.     

Folding 2D Structures into 3D Configurations at the Micro/Nanoscale: Principles,Techniques, and Applications

Compared to their 2D counterparts, 3D micro/nanostructures show larger degrees of freedom and richer functionalities; thus, they have attracted increasing attention in the past decades. Moreover, extensive applications of 3D micro/nanostructures are demonstrated in the fields of mechanics, biomedicine, optics, etc., with great advantages. However, the mainstream micro/nanofabrication technologies are planar ones; therefore, they cannot be used directly for the construction of 3D micro/nanostructures, making 3D fabrication at the micro/nanoscale a great challenge. A promising strategy to overcome this is to combine the state‐of‐the‐art planar fabrication techniques with the folding method to produce 3D structures. In this strategy, 2D components can be easily produced by traditional planar techniques, and then, 3D structures are constructed by folding each 2D component to specific orientations. In this way, not only will the advantages of existing planar techniques, such as high precision, programmable patterning, and mass production, be preserved, but the fabrication capability will also be greatly expanded without complex and expensive equipment modification/development. The goal here is to highlight the recent progress of the folding method from the perspective of principles, techniques, and applications, as well as to discuss the existing challenges and future prospectives.