基于微流控技术实现严格厌氧条件下的细菌单细胞培养与实时观测

当下微生物研究存在两个趋势,一是随着大量肠道微生物相关研究的开展,研究者们越来越认识到肠道微生物尤其是大量厌氧菌与人类健康息息相关,因为肠道本身在某种程度上也属于厌氧环境,故对肠道细菌的细胞生理学研究需要建立在厌氧培养环境的基础之上;二是仅依靠经典的微生物群体培养方法已经难以满足对细胞异质性的研究,需要发展多种方法在单...     

微流体装置中超声流的研究

应用流体动力学的基本理论,建立起声流场的一维解析模型,对声波在管道内部传播时产生的声场和声流运动进行探讨。然后提出并设计了一种利用PZT激励微管道振动产生超声场的新型微流体装置。该装置为由微管道相连接的两个微腔体,并利用有限元法对超声波激励的微管道和腔体进行瞬态的流场数值分析,得到一阶声压和流场的速度分布结果,最后对数值结果进行处理并讨论了超声波在管道内传播时产生的声流速度以及驱动力的分布情况。     

Microfluidic devices harboring unsealed reactors for real-time isothermal helicase-dependent amplification

High-throughput microchip devices used for nucleic-acid amplification require sealed reactors. This is to prevent evaporative loss of the amplification mixture and cross-contamination, which may occur among fluidically connected reactors. In most high-throughput nucleic-acid amplification devices, reactor sealing is achieved by microvalves. Additionally, these devices require micropumps to distribute amplification mixture into an array of reactors, thereby increasing the device cost, and adding complexity to the chip fabrication and operation processes. To overcome these limitations, we report microfluidic devices harboring open (unsealed) reactors in conjunction with a single-step capillary based flow scheme for sequential distribution of amplification mixture into an array of reactors. Concern about evaporative loss in unsealed reactors have been addressed by optimized reactor design, smooth internal reactor surfaces, and incorporation of a localized heating scheme for the reactors, in which isothermal, real-time helicase-dependent amplification (HDA) was performed.     

Automated Design and Programming of a Microfluidic DNA Computer

Previously, we described ways to implement the functions AND and OR in a DNA computer consisting of microreactors with attached heating elements that control annealing of DNA. Based on these findings, we have devised a similar device that can solve a satisfiability problem in any form. The device occupies linear space and operates in quadratic time, while a previously described competing device is built in quadratic space and operates in quadratic time or greater. Reducing the number of reactors in a DNA computer reduces the loss of DNA through binding to the surfaces of the system.     

基于无纺布检测浓度的微流控装置

目前微流控器件主要由玻璃或聚合物材料制成,而无纺布具有成本低、易加工、一次性等优点,为微流体材料提供了一种新的选择。本研究把蜡印染在无纺布上制备微流控器件,可以形成有效的蜡印通道,控制流体在内部通道扩散和流动。并把不同浓度的红色水溶性染料滴到通道中,利用图像处理算法检测其灰度值做浓度比对,发现在特定浓度下,灰度值呈现近似线性规律,可将其推广到生物医学现场检测等领域。     

Microfluidic Device for Coupling Capillary Electrophoresis and Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry

We have designed and fabricated a polydimethylsiloxane (PDMS) microfluidic device for coupling capillary electrophoresis (CE) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). The coupling is advantageous in biological research because CE has the power of separating analytes in a sample based on mobility difference and MALDI-MS provides accurate and sensitive mass analysis of the analytes. The goal is realized by fractionating the separated analytes inside the microfluidic device and pushing the analyte fractions into open reservoirs. Each analyte fraction is then mixed with a matrix solution and deposited on a MALDI target for MALDI-MS. Therefore, a two-step analysis of analytes in the form of CE-MALDI-MS is achieved by using the microfluidic device.     

Impedance Microbiology-on-a-Chip: Microfluidic Bioprocessor for Rapid Detection of Bacterial Metabolism

Detection of a few live bacterial cells in many industrial or clinical samples is a very important technological problem. We have developed a microscale technique for concentrating bacterial cells from a dilute sample, by factors on the order of$10^4$to$10^5$, and detecting their metabolic activity by purely electrical means. The technique was implemented on a silicon-based microfluidic chip where the cells are concentrated and incubated in a chamber with a volume of 400 pL. Concentration and capture are obtained by the use of dielectrophoresis on the bacterial cells, and metabolism detection is achieved by means of impedance measurements of the medium in which the bacteria are incubated. Performing impedance-based detection at the microscale results in drastically reduced detection times for dilute bacterial samples, thanks to the ability to efficiently concentrate and capture the cells in an extremely small volume. Such concentration eliminates the need to amplify the bacterial population by long culture steps. This detection technique can be used for a wide variety of applications.hfillhbox[1386]     

A Micromachined Kelvin Probe With Integrated Actuator for Microfluidic and Solid-State Applications

This paper reports on a micromachined Kelvin probe structure with an integrated scanning tip and an integrated electrothermal actuator that provides axial dithering motion. The device is fabricated from metal foil by a modified microelectrodischarge machining process that allows electrical isolation within the device. In particular, it permits the incorporation of a wide epoxy plug that creates an insulating gap with low parasitic capacitance between the probe and the actuator. The epoxy structures are found to withstand the thermal and mechanical conditions encountered during device operation. The device is used to measure changes in the external surface potential of a parylene microfluidic channel as a function of varying pH of liquid inside the channel. A contact potential difference of$approx 6~ V$is measured for a change in pH from 4 to 8 within the channel. The device is also used to map embedded charge in a thin$ SiO_2$layer on a Si substrate, showing it to be suitable for monitoring microelectronics manufacturing processes.hfillhbox[1072]     

网络化测量装置设计中的服务器集成技术

提出服务器集成概念,将HTTP、FTP和用户自定义TCP 测量协议集成,用一个端口和线程来提供所有网络服务.设计了一种网络化数据采集器,用作Internet的共享设备.     

High-Voltage Dielectrophoretic and Magnetophoretic Hybrid Integrated Circuit/Microfluidic Chip

A hybrid integrated circuit (IC)/microfluidic chip is presented that independently and simultaneously traps and moves microscopic objects suspended in fluid using both electric and magnetic fields. This hybrid chip controls the location of dielectric objects, such as living cells and drops of fluid, on a 60 $times$ 61 array of pixels that are $30 times 38 mu hbox{m}^{2}$ in size, each of which can be individually addressed with a 50-V peak-to-peak dc-to-10-MHz radio-frequency voltage. These high-voltage pixels produce electric fields above the chip's surface with a magnitude $vert vec{E}vert approx 1 hbox{V}/muhbox{m}$ , resulting in strong dielectrophoresis (DEP) forces $vert vec{F}_{ rm DEP}vert approx 1 hbox{nN}$. Underneath the array of DEP pixels, there is a magnetic matrix that consists of two perpendicular sets of 60 metal wires running across the chip. Each wire can be sourced with 120 mA to trap and move magnetically susceptible objects using magnetophoresis. The DEP pixel array and magnetic matrix can be used simultaneously to apply forces to microscopic objects, such as living cells or lipid vesicles, that are tagged with magnetic nanoparticles. The capabilities of the hybrid IC/microfluidic chip demonstrated in this paper provide important building blocks for a platform for biological and chemical applications. $hfill$[2009-0142]      

为WinPE系统集成设备驱动的一次尝试

WinPE在启动时会读取TXTSETLTP.SIF内容,用文本安装模式加载第三方驱动.利用这一功能我们可以把驱动封装到WinPE启动系统中.     

电力机房一体化可信监控装置设计

提出了一种新型机房一体化可信监控装置设计方案.该方案所选核心芯片LS1043A具备超强边缘计算能力,利用PCIe总线扩展构建7个数据通道,桥接远端业务终端与功能扩展板,支持四遥、串口、4G/5G模块业务应用,亦可根据具体需求适配不同类型扩展板,另外通过6路千兆以太网网络衔接智能化远程监控终端.本方案高效实用,充分利用P...     

基于模糊模型的结构和参数的一体化辨识

基于模糊集合的模糊建模捕述复杂、病态、非线性系统的特性是一种有效方法．文中讨论了从样本数据中通过正交变换和模糊聚类获取模糊规则的方法．利用正交最小二乘对模糊聚类的结果进行变换,采用CGS（Classical Gram—Schmidt）方法确定对建模贡献大的规则,删除对建模贡献小的规则,并对模型中的参数进行估计,能够同时模对糊模型的结构和参数进行辨识．仿真结果表明,提出的方法能够对非线性系统进行模糊建模．     

An Integrated 2-D Active Optical Fiber Manipulator With Microfluidic Channel for Optical Trapping and Manipulation

We report a new two-axis active optical fiber manipulator for on-chip optical manipulation and detection in microfluidic environment. The system comprising of air chambers, fiber channels, controllable moving walls, and membrane structures were fabricated by using microelectromechanical systems technology. By adjusting air pressures to control the deflection of the pneumatic chambers placed orthogonal to and underneath the fiber channels, accurate alignment of a pair of approximately coaxial optical fibers, which was indicated by maximizing fiber-to-fiber optical-coupling measured in real time, has been achieved. A maximum displacement of a buried fiber as large as 13 mum at an applied pressure of 40 lb/in² for one air chamber has been demonstrated. It was sufficient to accurately align two approximately coaxial optical fibers to maximize the optical coupling efficiency. The maximum coupling efficiency for two single-mode optical fibers facing each other at a distance of 200 mum was measured to be 4.1%. The following features have been successfully demonstrated with this system: 1) stable optical trapping and stretching of a single red blood cell; 2) stable optical trapping of multiple microparticles; 3) optically driven controlled motion of single and multiple microparticles; and 4) integration of a counterpropagating dual-beam trap with single-beam optical tweezers. In addition to optical trapping and manipulation, the proposed device is promising for applications requiring coaxial input/output fibers for in-line optical analysis. Furthermore, it can be easily integrated with other microfluidic devices such as microcapillary electrophoresis channels or microflow cytometers for DNA, protein, and cell analysis.