一种离心式微流控生化分析芯片

文章介绍了一种低成本、快速、自动化的离心式微流控生化分析芯片。该芯片通过整合样本前处理和多生化指标检测,采用了多级微流道与虹吸微阀相结合的方式把样本的前处理、样本输送、样本与生化试剂反应等过程集成于一体,并通过比色检测获得各个生化检测项目的结果。实验结果显示芯片比色孔光程的精密度的变异系数在0.08%~0.52%,通过血糖结果的精密度评估的芯片对样本和稀释液定量以及两者混合的精密度变异系数为1.4%,同时使用芯片测定15个生化项目的日间和批内精密度均小于3.5%,这表明该离心式微流控生化分析芯片符合临床检测要求。     

Discrete Chemical Release From a Microfluidic Chip

We demonstrate a discrete chemical release method, capable of delivering picoliter volumes of chemical solutions with 100 mum of spatial resolution and 20 mus of response time. The releasing mechanism is based on the transfer of pulsed liquid plugs through a hydrophobic air chamber. A microfluidic chip consisting of such a releasing array (2 times 10) is designed and fabricated. Numerical simulation and experimental testing are performed to verify the working principle. Advantages of this release-on-demand technology include leakage-free, fast response and versatile control of release profile. This new method could be a key enabling technology for precisely controlled release of biochemicals for modern pharmacological and biological research.     

基于FPGA的微流控芯片电泳控制系统设计

设计一套基于FPGA的微流控芯片的电泳控制系统。该系统采用具有大量控制端口的FPGA作为系统的控制芯片,同时为了节约控制端口,选取串行控制的A／D与D／A芯片;采用USB2.0高速传输接口与上位机通信,满足了实施控制与数据上传的要求;采用VerilogHDL语言对芯片编程后,可同时对30个PCR芯片实施控制,另外还编写了基于Windows XP的驱动程序与控制软件。     

基于离心式微流控芯片的生化分析仪控制系统

针对POCT(point of care testing)场合对自动化、小体积和易操作的生化分析仪的需求,为基于离心式微流控芯片的生化分析仪设计一种基于ARM,MCU和DSP的多处理器控制系统。以S5 PV210(ARM)为上位机,负责友好的人机交互、任务分配、数据管理等工作;以C8051 F060(MCU)和TMS320F28335(DSP)为下位机,负责运动控制、数据采集等实时性要求高的工作。多处理器采用串行通信,协同工作,多任务并行处理。采用嵌入式Linux为操作系统,Qt/Embedded为应用程序开发工具。实验结果表明,系统快速、稳定、操作简单,满足生化分析仪的POCT使用要求。     

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]      

面向电阻抗成像检测的多电极阵列微流控芯片设计

设计了一种用于微尺度流动状态下电阻抗成像检测的多电极阵列微流控芯片,包括微流控芯片的结构设计、材料选择和加工工艺。设计的微流控芯片包含3个圆形电极横截面,每个横截面包含一组电极阵列。该阵列有3种数目的电极,分别为8电极,12电极和16电极。之后通过数值仿真方法实现了三种电极数目（8,12和16）微流控芯片的电阻抗成像,并与之前研究出来的菱形横截面8电极微流控芯片进行了对比,发现设计出来的16电极圆形微流控芯片具有较高的成像质量,验证了微流控芯片用于细胞电阻抗成像检测的可行性。     

基于图像处理的微流控芯片智能定位系统

针对微流控芯片分析系统中微管道检测手动定位方式定位精度低、耗时费力及无法完成跟踪定位等缺点，设计了一种基于图像处理技术的微流控芯片智能定位系统。系统采用形态学方法、细化算法及Radon变换等相关图像处理方法将芯片平面图上微管道的节点提取出来，生成邻接表，以完成对微流控芯片的智能跟踪定位，并通过定位结果对邻接表进行反馈修正。实验表明所提出的智能跟踪定位方法在对微流控芯片进行跟踪定位时效果良好。     

纸基微流控芯片技术及在水质检测中的应用

纸基微流控芯片技术是一种以纸张为基底材料,通过喷墨、光刻等技术进行加工的新型微流控技术.纸张具有造价低廉、样品消耗少、简单便携和环境友好等优点,很大程度上促进了芯片实验室集成化和微型化的发展.近些年,随着社会经济的不断发展,水环境污染问题日渐严重,对水环境的污染分析研究备受关注,传统的检测和分析技术不适用于现场快速测定,纸基微流控芯片技术凭借着材料来源广泛、成本低、便携性等优点在水质检测领域受到了广泛关注.文章介绍了微流控基底材料的选择,芯片2D和3D的制作方法,比色法、荧光法和电化学分析法等用于纸基微流控芯片的检测方法,以及纸基微流控芯片技术在水质检测领域中重金属、富营养化元素和有机污染物检测方面的应用,最后对该技术在未来可持续发展中朝着集成化、低成本、高灵敏的智能化检测方向发展进行了展望.     

基于微流控芯片的单细胞图像观测系统的设计

目的:微观检测福尔马林固定单细胞病理实验的固定过程。方法:在恒温条件下,在微流控芯片上培养活体细胞样品,对细胞核DNA进行染色,利用液体静压力驱动和电渗驱动相结合的方式将细胞输送到图像观测位置,注入10中性福尔马林浸泡,利用荧光显微镜观察细胞固定过程中的形态变化。结果:基于微流控芯片的单细胞图像观测系统的设计认知和总结福尔马林对组织细胞"固定"的作用效果和应用价值。结论:对福尔马林细胞固定作用效果的总结,使工作实践有所借鉴,充实专业内容,进一步提高病理制片质量。     

集成惯性聚焦结构的介电泳微流控芯片的粒子连续分离

设计并制造了一种带有惯性聚焦结构的介电泳微流控芯片,以实现不同介电性质的粒子连续分离.采用MEMS工艺制作了介电泳微流控芯片:通道入口侧壁设置一对梯形结构使经过的粒子受惯性升力的作用聚焦到通道两侧;通道底部光刻一组夹角为90°的倾斜叉指电极产生非均匀电场,利用介电泳力和流体曳力的合力使通道两侧不同的粒子发生角度不同的偏转进入不同通道,从而实现分离.将酵母菌细胞和聚苯乙烯小球作为实验样本,分析了流速和交流电压对分离的影响,确定了二者分离的最优条件并进行分离.实验结果表明,将电导率为20μS/cm的样本溶液以5μL/min的流速注入到通道中,施加6 Vp-p、10 kHz的正弦信号,酵母菌细胞沿电极运动至夹角处后沿通道中心排出,聚苯乙烯小球沿通道两侧排出,成功实现分离,平均分离效率达92.8％、平均分离纯度达90.7％.     

Formation of Microdroplets in Liquids Utilizing Active Pneumatic Choppers on a Microfluidic Chip

Monodispersed emulsions are of great significance for a variety of applications. The current study reports a new microfluidic system capable of formation of microdroplets in liquids for emulsification applications. This new emulsion chip can precisely generate uniform droplets using a novel combination of hydrodynamic-focusing and liquid-chopping techniques. Experimental data show that microdroplets with diameters ranging from 6 to 100 mum with a variation less than 3% can be precisely generated. The size of the droplets is tunable using three approaches including adjusting the relative sheath/sample flow velocity ratios, the applied air pressure and the applied chopping frequency. Moreover, focusing and chopping of multiple flows has been demonstrated to increase the emulsion process throughput     

基于微流控芯片的钙离子浓度检测系统的实现

在细胞内物质定量分析中引入微流控芯片.利用微流控芯片完成细胞的培养、染色、试剂的进给等生物实验功能.设计了用于细胞内钙离子浓度检测的微流控荧光检测系统.通过双波长激发,利用荧光检测系统完成荧光强度和图像的采集.同时研究比值荧光法,计算出定量检测的钙离子浓度.实验结果表明,此检测装置可靠性高,检测结果准确.这一研究,提供了一种细胞检测新手段.为细胞研究提供更加便捷的细胞培养、检测、试剂进给一体化检测装置.     

一种无阀微流体驱动器的研究

一种适用于微流体系统的无阀驱动器利用印刷电路板(PCB)制作腔体以及扩散口和喷口,利用聚二甲基硅氧烷(PDMS)作为振动膜,并利用压电双晶片作为驱动部件。该驱动器的制作工艺简单,使用寿命长,具有良好的液体驱动性能。对于使用15mm长的压电双晶片制作的驱动器,在100V、60Hz、占空比为1的方波驱动下,最大流速可达l50μL/min。     

基于小波能量元和改进双阈值函数的微流控芯片信号去噪方法研究

微流控芯片技术是一种新型的分析检测技术,可广泛应用于生物、化学、医学等领域。为提高微流控芯片信号去噪效果,本文提出了一种基于小波能量元和改进双阈值函数的去噪方法。构建了基于指数和对数函数的小波能量元双阈值函数,继而设计了微流控芯片信号去噪算法。以模拟的微流控芯片信号为研究对象,对比选择db4小波基进行了4层分解去噪仿真实验。仿真结果表明,本文方法优于现有的普通阈值法、空域相关法和能量元浮动阈值法。该方法已应用于自主研发的非接触式微流控芯片便携式分析诊断仪,去噪效果良好,有效提升了设备性能。     

一种CLF芯片与SIM卡芯片连接的方法

在NFC技术中,CLF芯片与SIM卡的连接是一个重要问题,本文提出了一种具有自主知识产权的CLF与SIM卡的通信方法,采用新的调制解凋方式,使得S2信号在S1信号高低电平时都能传输,实现单线连接NFC与SIM卡,以及它们之间的全双工通信.通过对该方法进行电路级的设计和仿真,验证了该方法的正确性和稳定性.     

A Color Coordinate Normalizer Chip

The use of multispectral images of the same object considerably increases the opportunity for unique selection of features. The use of color information has been receiving growing attention. This paper presents the design and VLSI implementation of a new ASIC, which performs real-time conversion of the raw RGB data into the rgb normalized color coordinates. The high speed of operation is achieved by pipelining the data in a vector fashion. Eight-bit color images have been used, since this resolution is adequate for encoding the composite video signal without noticeable degradation. The inputs to the circuit are the RGB data obtained from a color sensor and digitized through three flash ADCs. The design has been implemented using the CADENCE VLSI CAD tool. The die size dimensions for the core of the chip are 1.87 mm × 1. 80 mm = 3. 37 mm², for a DLM, 0.7 m, N-well, CMOS technology and its maximum frequency of operation is 30 MHz. The ASIC is intended to be used in real-time pattern recognition applications, such as robotics, military systems, food, printing, pharmaceutical and agricultural industries. Real-time techniques are important not only in terms of improving productivity, but also in reducing operator errors associated with visual feedback delays.     

A/D芯片TLC2543与Neuron芯片的接口应用

介绍了LonWorks技术中的Neuron芯片的一种I／O应用模式，A／D芯片，TLC2543的串行接口特性以及Neuron芯片与A／D芯片构建的多通道12位模拟数据采集系统，并介绍了相关的硬件和软件设计。     

Dynamic Microfluidic Photomasking

This paper presents a novel microfluidic photomasking strategy. Laminar microfluidic streaming is exploited to achieve photomasking with dynamic spatial control. Two light-absorbing streams hydrodynamically focus a transparent stream to define a line of light transmission. A device incorporating two such microfluidic layers, which are aligned orthogonally, enables light transmission only where the transparent streams overlap. Control of fluid flow in the microfluidic layers enables dynamic spatial control of the exposed region. The dynamic microfluidic photomasking strategy is tested through transmitted light microscopy and applied to microfabrication via photoresist patterning. When applied to microfabrication in a frontal photopolymerization mode, this method affords both planar and depthwise control of feature geometry.     

Microfluidic whole-blood immunoassays

Immunoassay is one of the most widely used biomedical diagnostic methods due to its sensitivity and specificity. Microfluidic lab-on-a-chip technology has the advantages of portability, integration, and automation. The combination of these two technologies leads to a pathway for point-of-care diagnostics using the unprocessed samples such as the whole blood. This article reviews the recent advancement and the major development in the microfluidic-based whole-blood immunoassays. After a survey of the recent studies on microfluidic whole-blood immunoassays, an in-depth review about the detection methods that can be miniaturized and integrated in the immunoassay chips is provided. Point-of-care diagnostics applications require developing a fully integrated, disposable, low-cost, and handheld microfluidic device for the whole-blood immunoassay. In this regard, some comments and suggestions for future research are given.