Fabrication of Robust 2-D and 3-D Microfluidic Networks for Lab-on-a-Chip Bioassays

We describe a new method for the fabrication of robust three-dimensional (3-D) lab-on-a-chip devices comprising microfluidic channels and integrated electroanalytical sensors and show their potential application in supporting leak-free pressure driven fluid flow. The technology is based upon the lithographic patterning of a soluble negative photoresist and an insoluble, crosslinked, positive photoresist (SU-8) to produce the pattern of a large area microfluidic network, followed by coating the pattern with silicone rubber or PDMS. After curing, immersion in acetone rapidly elutes the soluble resist to yield the network of channels. As a result the channels formed are robust and it is possible to fabricate a device that supports fluids flowing at high flow rates (without leakage) without the need for special pre-treatment or surface modification of the substrate or silicone covering. We also demonstrate the flexibility of the methodology by producing more complex fluidic networks that comprise bridges which enable one fluid stream to pass over (and remain physically separated from) a second fluid stream. The sealing and packaging techniques, developed for this process do not require the use of extreme conditions and are thus compatible with a broad range of lithographic processes (including, for example, the definition of and incorporation of in situ electrochemical sensor elements). Finally, measurements on a model bioelectroanalytical system applicable to analysis of a model immunoassay are shown, demonstrating the application of this new fabrication method in developing reproducible analytical methods within an encapsulated device.hfillhbox[1297]     

Free-Form Simulation of Sequential Etching and Surface Characterization for 3-D MEMS Fabrication

A new diffusion-based simulation model of isotropic wet etching and free-form surface characterization method for 3-D free-form microelectromechanical systems (MEMS) fabrication is presented in this paper. To simulate the etching process, a diffusion-based model solved by the finite-element method (FEM) has been developed, allowing extraction of more accurate etch-front data at discrete time steps. In the developed method, free-form MEMS objects are modeled as B-spline functions with material concentration. Finite elements are generated by discretization in the parametric domain of the free-form object and mapping back to the Euclidean space. Points on the etch front are extracted using a Z-map method. The extracted point data are characterized to obtain a B-spline representation of the etch-front surface. Examples from the isotropic etching simulation of 2-D and 3-D objects with both regular and free-form geometry are presented. The developed method allows the simulation of 3-D objects with free-form input and free-form mask opening and facilitates the simulation of sequential etching of free-form objects with irregular mask openings. This paper also discusses applications of the developed method in MEMS process planning that can be realized by taking advantage of the better control of geometry that it provides in MEMS fabrication.     

自动化立体仓库控制系统设计

为满足大载重、高速、高精度立体仓库控制系统的自动化运行要求,设计了一种PLC控制器和伺服控制相结合的控制系统方案。系统采用了三菱以太网、H网、CC-Link和串口通信等不同层次、不同通信协议的通信网络来满足现场复杂环境的通信需求,并采用三菱伺服的半闭环、全闭环等多种控制方式来满足生产对系统的运行速度、精度和平稳性的需求。实际运行效果表明,该控制方案较好地适应了现场生产环境,实现了系统安全、稳定的运行,满足了各项生产需要,大大节约了人力和物力。     

Fabrication and characterization of truly 3-D diffuser/nozzlemicrostructures in silicon

We present microfabrication and characterization of truly three-dimensional (3-D) diffuser/nozzle structures in silicon. Chemical vapor deposition (CVD), reactive ion etching (RIE), and laser-assisted etching are used to etch flow chambers and diffuser/nozzle elements. The flow behavior of the fabricated elements and the dependence of diffuser/nozzle efficiency on structure geometry has been investigated. The large freedom of 3-D micromachining combined with rapid prototyping allows one to characterize and optimize diffuser/nozzle structures     

热超声倒装键合中温度对对准精度的影响

针对热超声倒装键台过程中芯片与基板的对准精度受温度影响,采用了6参数仿射模型分层搜索算法分别研究了温度影响下序列图像间平移、伸缩、旋转参数的分布规律;分析结果显示,随着温度的升高,湍流强度增强,图像间平移,伸缩、旋转运动越剧烈,对应参教的离散程度也越高;在键合温度下,伸缩与旋转对对准精度影响不大,可以忽略;平移最大可达6个像素,必须将平移量控制在亚像素级范围内才能满足芯片与基板的对准精度要求.     

数字三维景观信息展示系统

本文详细介绍了我们用VC研制开发的数字河北三维景观展示系统技术流程。该系统具有场景三维漫游控制、航线设计、信息查询与分析、分层注记显示、三维坐标查询、实时定位等功能。具有使用方便、直观等特点。     

3-D Tag-Based RFID System for Recognition of Object

Generally, object recognition in robotics has used vision, sonar, laser range sensors, etc. In this paper, the authors propose a new sensing technology based on radio frequency identification (RFID) to facilitate the autonomous recognition of objects. This technology uses a novel tag, named the 3-D tag, with which an object can be identified and its orientation together with location can be estimated. This paper presents the method for object recognition by analyzing the characteristics of the 3-D tag, and then validates the 3-D tag through several demonstrations showing its usefulness as an independent sensor for recognizing objects.     

三维焊接坡口轮廓图像测量系统

开发了一种三维焊接坡口轮廓图像测量系统,该系统基于光栅莫尔条纹投影原理,由LD、光栅副、滤光片、面阵CCD（Charged coupled device）及DSP图像信号处理等部分组成。分析了在恶劣的焊接现场条件下,莫尔条纹投影到焊接工件表面的噪声产生机理,提出并采用了中值滤波方法对采集的原始激光焊缝图像信号进行平滑处理。由CCD采集到的焊接坡口表面变形的莫尔条纹二维激光图像,经过图像信号处理软件后恢复焊接坡口的三维轮廓图像,获得焊缝中心、深度、宽度等参数的精确尺寸信息。该测量系统经过在轻便型焊接机器人上试用,其测试精度、实时性基本能满足要求。实验结果表明该方法简单可靠、效果明显。     

三维几何造型设计自助学习软件系统

根据三维造型设计教学辅助和学习者自助学习的需要,基于工业造型设计软件Pro/Engineer,对该软件各种三维实体造型特征、辅助特征、装配过程配合方法等进行合理分类,选择具有表征性的特征模型分别对其应用过程进行静态和动态描述,并选择典型零件对各种特征的综合造型应用过程进行详尽地描述,利用VB6.0编程环境,将这些描述过程集成在一个统一的环境中,形成了该软件各种特征造型设计选项造型应用过程静态和动态描述软件系统。该软件可以用于三维造型设计辅助教学和自助学习,也可方便地用于企业产品设计技术人员的培训。     

立体几何造型系统图形数据库

一个实用的、完整的几何造型系统必须有一个精心设计的图形数据库作为图形信息的存贮和管理中心.本文以几何体的边界表示法为基础,提出了一个几何造型系统的图形数据库设计方法,并介绍了该方法在UNIFY关系数据库管理系统上的实现及C语言接口设计.     

A Galerkin Method for the Simulation of the Transient 2-D/2-D and 3-D/3-D Linear Boltzmann Equation

Many production steps used in the manufacturing of integrated circuits involve the deposition of material from the gas phase onto wafers. Models for these processes should account for gaseous transport in a range of flow regimes, from continuum flow to free molecular or Knudsen flow, and for chemical reactions at the wafer surface. We develop a kinetic transport and reaction model whose mathematical representation is a system of transient linear Boltzmann equations. In addition to time, a deterministic numerical solution of this system of kinetic equations requires the discretization of both position and velocity spaces, each two-dimensional for 2-D/2-D or each three-dimensional for 3-D/3-D simulations. Discretizing the velocity space by a spectral Galerkin method approximates each Boltzmann equation by a system of transient linear hyperbolic conservation laws. The classical choice of basis functions based on Hermite polynomials leads to dense coefficient matrices in this system. We use a collocation basis instead that directly yields diagonal coefficient matrices, allowing for more convenient simulations in higher dimensions. The systems of conservation laws are solved using the discontinuous Galerkin finite element method. First, we simulate chemical vapor deposition in both two and three dimensions in typical micron scale features as application example. Second, stability and convergence of the numerical method are demonstrated numerically in two and three dimensions. Third, we present parallel performance results which indicate that the implementation of the method possesses very good scalability on a distributed-memory cluster with a high-performance Myrinet interconnect.     

面向航空发动机的高精高频动应变测量系统

高速高精动应变监测技术是实现航空发动机旋转部件故障早期诊断目标的关键技术。提出了一种基于相位解调技术的光纤法布里-珀罗(Fabry-Pérot, F-P)动应变测量系统,实现了在高频率条件下的高精度动应变测量。实验结果表明：系统中F-P传感器对应变的灵敏度可以达到100.955 pm/με,约为一般光纤FBG应变传感器(应变约1 pm/με)的100倍;测量频率可以达到10 kHz;在对多种不同标准激振频率进行测量时,误差不超过1.1%;另外测量系统探头能耐受1 200℃的高温,因而在未来航空发动机旋转部件故障监测、性能测试方面都具有较好的应用前景。     

计算机辅助三维非接触测量系统的研究与应用

本文对三维非接触测量进行了简单介绍,着重对其中的投影栅相位法从光学原理、相位原理和相位解包裹三个方面分别作了详细的阐述,实例分析结果证明该方法具有较快的测量速度和准确度.     

颅颌面三维成像测量系统的研究

通过计算机图像处理对分期摄得的X光正、侧位片来重建颅颌骨三维图像.分期摄取颅颌骨的正、侧位片,通过数学方法获取特征点的精确坐标,依此重建颅颌骨的三维图像,并可从任意角度全方位观察和定量测量和定性分析,优化医患界面.     

A Constraint-Satisfaction Approach for 3-D Object Recognition by Integrating 2-D and 3-D Data

We present a framework for recognition of 3D objects by integrating 2D and 3D sensory data. The major thrust of this work is to efficiently utilize all relevant data, both 2D and 3D, in the early stages of recognition, in order to reduce the computational requirements of the recognition process. To achieve this goal, we formulate the problem as a constraint–satisfaction problem (CSP). Rather than directly solving the CSP, a problem of exponential complexity, we only enforce local consistency in low-order polynomial time. This step of local-consistency enforcement can significantly decrease the computational load on subsequent recognition modules by (1) significantly reducing the uncertainty in the correspondence between scene and model features and (2) eliminating many erroneous model objects and irrelevant scene features. A novel method is presented for efficiently constructing a CSP corresponding to a combination of 2D and 3D scene features. Performance of the proposed framework is demonstrated using simulated and real experiments involving visual (2D) and tactile (3D) data.     

高精度激光扫描系统的设计及数据融合

为了解决在机载激光雷达(Lidar)系统中姿态测不准的难题,提出了采用分立传感器设计的方案,与传统的集成IMU (Inertial measurement unit)设计方案相比,分立设计的方案具有灵敏度高,精度高,噪声低,漂移小等优点;系统主要介绍了分立姿态系统设计方案和软件设计的思想并搭建了激光扫描的数据链路系统;根据各个传感器的特点,结合高阶卡尔曼滤波算法进行有效地数据融合,经实验验证,该系统能够得到高效率、高精度的激光点云数据;这些数据经过地面站上的校正、配准和三角化滤波算法之后能够得到满足工程应用的三维地形图.     

高精度数字式飞机水平测量系统

讨论了某型飞机高精度数字式水平测量系统的研制;系统硬件由便携式计算机和电子全站仪组成,在硬件设计中解决了飞机对称面的标定、单棱镜的固定等技术难点;系统软件采用Windows环境下的Visual Foxpro6.0进行编制;系统自动化程度和测试精度高、可靠性好,具有较好的应用前景。     

水下机器人三维可视化控制系统

研究水下机器人可视化系统问题,由于海洋作业情况复杂,存在弱观测、大时滞环境中机器人的稳定性和实时性差,控制显得尤为困难。针对目前可视化系统开发难度大、周期长的缺点,提出了一种WPF技术的三维可视化系统的设计方案,包括3DSMAX几何建模,Expression Blend 2三维可视化实现和Visual Studio 2008控制代码设计。结果表明,采用改进的泛化图形环境的方法为水下机器人可视化系统的实现提供了一种高效、简易的途径。经水池实验证明,系统能够对水下机器人进行实时可视化显示并完成操控任务。     

A Supervisory Wafer-Level 3D Microassembly System for Hybrid MEMS Fabrication

Hybrid MEMS (microelectromechanical systems) integrate solid-state ICs with MEMS sensors and actuators. It is widely believed that such systems will bring fundamental technological impacts and significant social benefits. Hybrid MEMS manufacturing requires the development of new fabrication, packaging and interconnection technologies in which microassembly plays a critical role. Microassembly is the assembly of objects with microscale and/or mesoscale features under microscale tolerances. It integrates techniques from many different areas such as robotics, computer vision, microfabrication and surface science. This paper studies the design and implementation of microassembly systems through the introduction of a supervisory microassembly workcell. This workcell is developed for 3D assembly of large numbers of micromachined thin metal parts into DRIE (deep reactive ion etching) etched holes in silicon wafers. It overcomes a major limitation of current MEMS fabrication techniques by allowing the use of incompatiable materials and fabrication processes to build complex-shaped 3D MEMS structures. The system is able to perform reliable and efficient wafer-level microassembly operations within a supervisory framework. Microassembly brings new and unique issues to robotics research. The major components of microassembly systems are analyzed. Results on micromanipulator design, illumination modeling and control, and microgripper design are presented.     

Fabrication and performance of 2-D compound X-ray refractive lenses

Due to the weak refraction of X-rays in matter, a focusing or deflection of X-ray using conventional refractive optics was not feasible. However, since compound X-ray refractive lens (CXRL) with consecutive holes array was proposed, it becomes currently a noticeable issue in X-ray optics. In this paper, we report on fabrication and performance test of two types of PMMA (polymethyl methacrylate) CXRLs. Firstly, one dimensional refractive X-ray lenses of parabolic and circular shape is fabricated by LIGA process. Based on the results, we conduct a fabrication of 2-D CXRLs. Here we suggest a LIGA-self align method which doesn’t need a special align equipment and is simpler method than conventional one. Through performance tests, we show experimentally that CXRLs are novel optical components for the hard X-ray range of about 8 keV and that they have possibilities to apply the X-ray optics for micro-focusing, imaging, and lithography.