碳纳米管原子力显微镜针尖的制作研究

研究在光学显微镜下，运用两个独立的三维工作台分别控制针尖和碳纳米管的位置，将碳纳米管吸附在传统的原子力显微镜针尖上。首先将碳纳米管粘附在导电的胶带上，然后用涂胶的针尖与其接触将碳纳米管粘附到针尖上，最后运用电蚀的方法优化碳纳米管针尖的长度，以达到高分辨率的要求。运用制作的碳纳米管针尖对硅表面的深槽进行成像，获得了传统针尖无法得到的信息。     

基于原子力显微镜的纳米加工研究

以原子力显微镜(AFM)作为加工工具对单晶硅进行了基于金刚石针尖的纳米加工试验,运用不同的方法对纳米加工区域的特性、材料在不同垂直载荷下的去除机理及切屑形成特征进行了系统的研究和分析,提出了一种在纳米尺度下研究加工机理的新方法。在此基础上,应用有限元法对AFM纳米加工中存在于金刚石针尖和被加工材料之间的接触作用机制进行了计算仿真。     

基于原子力显微镜(AFM)的微加工系统

目前原子力显微镜(AFM)已经成为纳米加工领域中一种重要的加工手段,但由于其自身扫描陶管及针尖等因素的影响,AFM的微加工能力在很大程度上受到限制。利用三维微动工作台结合原子力显微镜以及锋利的金刚石针尖组成微加工系统,通过编程获取微结构的轮廓,选择RS-232串口作为通讯方式,发送字符串命令控制工作台的运动实现预定的轨迹,从而消除了扫描陶管运动范围有限且存在漂移和滞后的影响,解决了氮化硅和单晶硅针尖加工材料范围有限的问题,提升了AFM的加工能力,并加工出较为复杂的微结构及微传感器。实验表明这是一种可行的微加工方法。     

表面增强拉曼光谱的研究进展

本文从提高表面拉曼光谱检测灵敏度和空间分辨率两个方面的发展叙述表面增强拉曼光谱和针尖增强拉曼光谱的原理、方法、特点以及最新进展。对利用表面增强拉曼光谱和针尖增强拉曼光谱研究金属表面上分子吸附等方面的应用进行总结 ,并对他们的应用前景做了预测     

微电极针尖的制备方法

针尖工艺是针型微电极制造的关键技术.利用电生理实验室常用设备搭建了加工平台,采用阴极圆环营造出一个渐变电场,通过一组正交试验,研究了电解液浓度、腐蚀电压、通电时间等对针尖质量的影响,得到了最佳加工参数:NaCl溶液浓度为3.0g/L,腐蚀电压为5.0V,通电时间为30s,制备出符合电刺激实验要求的高质量针尖.该方法操作简单、制备时间短、成本低,适用于电生理实验中微电极尖端形态的改进.     

微电极针尖的制备方法

针尖工艺是针型微电极制造的关键技术。利用电生理实验室常用设备搭建了加工平台,采用阴极圆环营造出一个渐变电场,通过一组正交试验,研究了电解液浓度、腐蚀电压、通电时间等对针尖质量的影响,得到了最佳加工参数：NaCI溶液浓度为3．0g／L,腐蚀电压为5．0V,通电时间为30s,制备出符合电刺激实验要求的高质量针尖。该方法操作简单、制备时间短、成本低,适用于电生理实验中微电极尖端形态的改进。     

纳米操作加工过程定位检测问题研究

微纳米操作、加工、检测和控制在各个领域获得广泛的研究和应用,在微纳米层次上进行原位、定位的操作、检测、加工是经常遇到的问题。扫描探针显微镜技术(Scanningprobemicroscope,SPM)提供强有力的工具,人们利用其不同类型的针尖与相应样品表面产生的化学或物理作用达到目的。但扫描探针显微镜针尖同时用于检测、加工和成像,会因为针尖磨损、状态的改变,影响检测信息的准确性、可靠性,直接影响结果的判定。本文提出一种在微操作加工过程的定位检测技术,即操作过程工具和探针承担不同任务,工具负责加工操作,探针用于检测并定位于操作加工位置,进行了实验并分析讨论定位过程相关问题。     

纳结构的连续激光复合微纳探针刻划加工

为了加工形貌稳定且尺寸尽可能小的纳结构,建立了一套连续激光复合微纳探针的加工系统,并研究了光纤探针导光的连续激光辐照微纳探针的近场增强效应以及该系统的加工性能。首先,根据表面等离子体激元理论仿真分析了激光辐照原子力显微镜(AFM)探针的近场增强因子,并研究了微纳探针的针尖温度场和针尖热膨胀。接着,搭建了基于光纤探针导光的连续激光复合微纳探针的纳结构加工系统。最后,对聚乙烯片状材料样品进行了纳结构加工。结果显示:加工得到的纳米点尺度为200nm左右;纳米线的尺度为30~40nm。结果表明:光纤探针导光连续激光复合微纳探针系统避免了复杂的空间光路结构,是一种成本低廉,结构简单的系统,能够实现纳结构的加工。     

AFM针尖对胶原样品表面一种损伤现象的研究

用AFM对吸附于云母表面的胶原蛋白的研究过程中，观察到一种AFM针尖对样品损伤现象。在小范围的扫描过程中．胶原蛋白在AFM针尖的作用下。产生了明显的移动。改变了其原来平整、均匀分布的表面特征。此现象文献中也曾有报道，在本实验中能重复出现。本文进一步分析讨论这种现象产生的原因，对比了不同成像模式下AFM针尖对样品表面的影响。结果表明，用Tapping Mode(TM)，扫描过程对样品表面几乎不产生影响，但是Non Contact Mode(NCM)在扫描过程中对样品表面产生了损伤作用。证明了TM模式更适合于对生物样品的研究。实验还发现这种损伤的程度和扫描范围的大小、针尖扫描的方向有着很大关系。     

基于原子力显微镜的线宽粗糙度测量

给出采用原子力显微镜(Atomic force microscope,AFM)测量线宽粗糙度(Line width roughness,LWR)的分析步骤。分析线宽和LWR及其偏差随刻线横截面位置的高度变化的关系,线宽及其偏差和LWR及其偏差随刻线横截面位置的高度值增加而减小。分别采用四种边缘提取算子提取了碳纳米管针尖AFM测量的刻线顶部线宽边缘,计算了刻线顶部线宽和LWR,顶部线宽和LWR测量结果对边缘提取算子不敏感。结合被测单晶硅台阶的顶表面和底表面加工方法,提出采用各扫描线轮廓高度相等的方法校正AFM压电驱动器的z向非线性。比较了采用普通氮化硅探针针尖、超尖针尖以及碳纳米管针尖AFM测量名义线宽为1 000 nm刻线LWR的结果,显示采用三种针尖的LWR测量结果存在差异,但考虑到AFM分辨率,可认为测量结果基本相同。因此,为更精确描述刻线边缘,必须提高AFM分辨率。     

Deformation and flying height orbit of glass sheets on aerostatic porous bearing guides

Handling devices have been developed for liquid crystal display fabrication that are equipped with aerostatic porous bearing pads to feed large glass sheets while supporting them with compressed air in a non-contact state. The deformation behavior and the orbit of the flying height of glass sheets on porous bearing pads during the feeding process were investigated using the compressible Reynolds equation and Timoshenko's thin film theory. Theoretical and experimental results showed that glass sheets are easily deformed by the pressure distribution in the air film and that they tilt easily on the bearing pad during the feeding. The results also showed that the hole pitch for air suction and the interval between bearing pads arranged next to each other should be shorter to achieve more stable feeding of the glass sheets with a constant flying height.     

A method to include plastic anisotropy to orthogonal micromachining of fcc single crystals

Micro-abrasive jet machining (μ-AJM) is a fast and flexible technique for micro-patterning of brittle materials and can be combined with patterned mask made from a material with excellent photolithographic properties. Here, we demonstrate a fabrication method for the realization of a passive micromixer with third-dimensional feature by using a μ-AJM process with employing photopolymer as a mask on a glass slide target. We fabricated the mask using SU8, a photosensitive polymer, applied as a micro-pattern for μ-AJM process. The design and fabrication of the proposed micromixer is the first reported for such a device. Three glass layers were successfully bonded in a single step using a direct bonding method. These three bonded glass layers with micro-patterns etched on them were the realization of third-dimension feature on the micromixer design.     

Water collection techniques at very low flow rates including strong capillary effects

Milli-, micro- and nano-flow calibrations are important in several areas of pharmaceutical, flow chemistry and health care applications where volumetric dosage or delivery at given flow rates are crucial for the process. After developing a facility for the micro-flow range, METAS has developed a facility for flow rates from 50 nL/min up to 400 mL/min. The continuous collection of the flowing water into a beaker on a balance without having droplet formation for a continuous increase of the weighing values is a challenge (dynamic gravimetric method). This technique is often used to determine the flow rate over several orders of magnitude. In this paper, we describe the newly developed METAS piston provers and focus on the water collection techniques used for the flow rate determination of very low flow rates going as low as 50 nL/min by means of the dynamic gravimetric method. One water collection technique is to immerse the outlet needle into the water in the beaker. To reduce evaporation either a saturated environment is created or a layer of oil is added on top of the water. Another water collection technique is applied at the METAS facilities, where the outlet needle is positioned just over glass filters on top of the beaker to collect the water by means of a constant water bridge obtained independently of the flow rate. These two techniques are investigated for comparing the stability of the flow rate determination and the influence of the capillary forces acting due to the water or water-oil surface on the outlet needle and on the water bridge between the outlet needle and glass filters. The technique applied at METAS with the water bridge between outlet needle and glass filter reveals to be more stable for the flow rate determination and corrections due to capillary forces acting on the outlet needle can be neglected compared to the water collection technique with the immersed needle.     

Gasoline spray characteristics impinging onto the wall surface in suction air flow

This study investigates the spray characteristics before and after wall impingingment of gasoline spray in suction air flow. For this study, a rectangular model intake port was made of acrylic glass, and suction air was generated by using the forced air blower contrariwise. The injector for this study was a pintle-type port gasoline injector in which an air-assist adaptor is installed to supply assisted air. A PDPA system was employed to simultaneously measure the size and velocity of droplets near the wall. Measured droplets are divided into “pre-impinging droplets” with positive normal velocity and “post-impinging droplets” were negative normal velocity for the suction flow. The velocities, size distributions and Sauter mean diameter (SMD) of pre- and post-impinging droplets for varions injection angles and air-assists are comparatively analyzed.     

适用于压力驱动的PDMS/玻璃复合微流控芯片的制作

改进了适用于压力驱动的PDMS/玻璃复合微流控芯片的制作方法,可在20min内制作出厚度均匀、大小一致的PDMS芯片。通过对PDMS盖片进行光学处理后,既改善其表面的亲水性,又可与玻璃基片进行不可逆封接。通过在芯片储液池部位安装压驱入口接头,使注射泵或蠕动泵的流体运输管道与芯片微通道实现良好接合,操作简便、死体积小。是一种适用于以细胞分析为目的的微流控芯片构建方法。     

基于硅模具的Zr基非晶合金微零件吸铸制备

基于硅模具提出了一种吸铸成形Zr基非晶合金微零件的方法。采用真空氩弧熔化吸铸炉进行了非晶合金微零件吸铸成形实验,用红外热像仪测量了合金熔液温度,发现合金熔液在1116℃下能够完全复制宽3μm、深3μm的硅方形微槽结构且具有较好的表面形貌。随后分别采用带有多型腔和双层型腔的硅模具进行了吸铸成形实验,成功制备了模数为50μm的非晶合金微齿轮零件,微零件的硬度及弹性模量分别为6.49GPa和94.9GPa。实验结果表明,基于硅模具吸铸成形Zr基非晶合金是一种制备高精度、高表面质量、高性能微零件的有效方法。     

一种单晶硅振动环陀螺仪的设计与制作

介绍了振动环式陀螺仪的基本工作原理,分析了传统的振动环式陀螺仪所存在的缺陷.并针对这些问题,设计和制作了一种单晶硅式振动环陀螺仪.该陀螺仪采用硅玻璃键合工艺制作,利用振动环作为敏感元件,选取静电激励、电容检测的工作方式.设计陀螺仪的工作频率高于15 kHz,以降低了环境对陀螺仪性能的影响.陀螺仪的制作方法简单,只需要2块掩模板,便于批量化生产.     

Structural analysis of spinner for glass wool fabrication by axial angle variation of outlet

Journal of Mechanical Science and Technology - In the glass wool fabrication process, stress concentration occurs in the vicinity of the spinner outlet. In this study, the stress concentration in...     

光学检测下气浮支承的玻璃薄板变形

液晶玻璃基板在线检测过程中对玻璃板在垂直方向上的变形量有严格的要求,为了确定在指标要求光学检测精度下的喷嘴间距。本文基于弹性薄板的小挠度弯曲理论对气浮支承下的液晶玻璃板进行理论分析,推导出液晶玻璃薄板在吹吸喷嘴作用下的最大挠度计算公式,分析得出最大挠度与通孔间距的二次方、载荷集度成正比;通过Fluent对液晶玻璃基板气浮支承系统进行仿真,得到了不同的喷嘴孔间距下的载荷分布以及玻璃基板最大位移处受到载荷的准确值,从满足玻璃板最大位移要求、气膜面的压力分布状况及经济性方面综合考虑得到气膜单元的通孔横向间距范围,给出了采用气浮支承传输的液晶玻璃基板光学检测仪器的喷嘴布置参数,即喷嘴的合理间距应处于20~25mm之间。     

A new macro-micro dual drive parallel robot for chromosome dissection

This paper presents a parallel-structure system dually driven by six servo motors and six piezoelectric actuators. Due to the combination of macro and micro manipulators which are both of orthogonal structures, the proposed system possesses a concise structure as well as actuation isolation and output motion decoupling properties. By using a glass needle mounted on a six-dimensional force sensor in endpoint operating, this system can be applied to chromosome dissection that to make the whole process more efficient and automatic. The glass needle tip has a stroke of 106 mm in three linear motions and 18.7-arc-degrees in three angle motion directions, with servo motors adopted. It also has the resolution of 20 nanometers with the adoption of piezoelectric actuators. The kinematics, isotropy, decoupling and design considerations of the proposed robot are discussed. Workspace and resolution of both macro and micro manipulators are measured separately. The experiments are also conducted to show its capability in dissecting chromosomes.