一种微流控检测芯片的设计与工艺研究

设计并制作了一种PMMA材料的微流控检测芯片,利用外界气体驱动液体,用于实验样品的分析和检测.芯片的整体尺寸为86 mm×60 mm×4.5 mm,利用精密加工的方法进行加工.采用一种简单实用的溶胶.凝胶改性方法对微通道管路进行亲水处理,实验证明亲水性有明显提高.并分析了亲水性提高的机理.提出一种新的溶剂键合方法,在室温下对芯片进行键合.溶剂为二氯乙烷和无水乙醇按1:1混合的混合液.分析了不同溶液配比、键合时间和键合压力对键合效果的影响.同时,芯片上集成了多个阀,对阀膜材料的选择、粘接工艺进行了研究.     

柔性微型阀对静电驱动振膜微泵压力性能的影响

将最小能量法与均匀压力载荷下圆薄膜大变形半解析解相结合,分析了静电驱动柔性微型阀对静电驱动振膜微泵压升性能的影响。微型阀容积的引入会导致静电驱动振膜微泵的压升出现一定程度的降低,但降低幅度远小于阀门容积对常规定排量泵的影响。微型阀的阀片以柔性薄膜为基片,因此所需的关阀电压远远低于微泵泵腔的驱动电压,从而使静电微泵和微型阀运行的可靠性得到了极大的提高。     

具有微流量检测功能的集成微流量泵驱动结构

根据我们研制成功的铝硅双金属驱动微流量泵驱动结构的特点,本文介绍了一种实现微流量泵驱动结构与微流量传感器系统集成的方法。该方法在原微流量泵双金属驱动结构的单晶硅膜上集成制作了微流量传感器。这种一体化的集成驱动结构单元同时具有驱动功能和流量检测功能,并且制作工艺简单,为进一步实现与控制电路集成的集成微流量泵系统奠定了基础。     

基于MEMS的压电微泵建模与优化

以压电驱动的无阀微泵为研究对象,根据扩张管/收缩管的压力损失系数和连续方程,建立了无阀微泵的理论模型。利用有限元分析软件,建立了无阀微泵有限元模型,进行了耦合场仿真分析。模拟并分析了不同边界条件下驱动电压、电压频率、泵膜厚度、压电薄膜厚度和压电材料对无阀微泵输出特性的影响。仿真结果显示,无阀微泵具有很好的整流特性,并且驱动电压越大,输出特性越好。在局部固定边界条件下,当压电薄膜上施加电场强度为500 V/mm的驱动电压时,存在最优的压电薄膜厚度,使得微泵的输出流量最大。研究结果为无阀微泵的优化设计提供了依据。     

基于AMESim的新型PDMS微阀动态特性仿真研究

针对一种新型的可用于气动微流控芯片气压控制的电磁致动微阀的进一步研究和应用问题,在阐述了其结构和工作原理的基础上,利用AMESim软件建立了相应的动态仿真模型,对其流量、压力动态特性进行了分析,并且给出了该种微阀和传统气动电磁阀的流量、压力动态特性的对比分析结果.该种新型的电磁致动微阀由微流控芯片的上层PDMS平膜、具有微流道的下层PDMS厚膜和电磁致动器构成,电磁致动器通过安装在阀座上的玻璃片与PDMS微流控芯片实现了集成.而且,采用这种集成化的新型微阀的控制方式相较于传统采用气动电磁阀的控制方式,具有成本低、体积小、易于与微流控芯片集成等优点.研究结果表明,采用这种新型PDMS微阀对微流控芯片进行驱动和控制可以获得较好的动态特性,并且该研究对电磁致动微阀的进一步研究和应用提供了一定的理论指导.     

数字阀驱动机构控制技术研究

数字阀的工作原理是驱动机构直接驱动阀芯运动,驱动机构集成了伺服电机和滚珠丝杠,伺服控制器实现对驱动机构的精确控制,驱动机构的动态和静态特性决定了数字阀的动态静态特性。伺服控制器硬件设计采用了TI公司的TMS320F28069作为主控芯片,DRV8332作为驱动芯片的架构模式。同时,在软件算法上,引入了变增益和分段式PI的控制方法实现了对数字阀死区的有效补偿。实验结果表明,这种控制技术很好的满足了数字阀的性能要求。     

利用压电微泵驱动和脉动混合可控合成金纳米粒子

为了合成粒径均一、单分散性好的金纳米粒子,提出一种压电驱动式脉动微混合可控合成金纳米粒子的方法。该方法采用两腔三阀结构的压电微泵作为驱动源,结合Y形微混合器,基于两压电微泵脉动交叉式输出性能来实现多种不同混合模式的可控混合。利用Fluent软件对Y形微混合器内不同流量及频率下的混合效果进行了优化分析,优选出了压电微泵的控制参数。在实验室内设计、制作了用于金纳米粒子可控合成的系统样机,并开展了相应的金纳米粒子可控合成试验。试验结果表明：电压为40 V,频率为300 Hz时,合成的金纳米粒子粒径较为均一,分散性较好,该结果验证了文中所提方法的可行性。此方法亦可应用于其他纳米粒子的可控合成。     

通道型电磁常闭微阀结构参数优化

优化了通道型电磁常闭微阀的结构参数,以提高其工作性能。基于近似结构模型对结构参数进行理论分析;以泄漏率为指标,利用有限元方法仿真分析了微通道的宽度、高度,底膜厚度,顶膜厚度及电磁驱动机构压力等主要结构参数对泄漏率的影响。提取了经验公式,基于正交实验法研究了结构参数对泄漏率和开启率的影响。最后,结合理论分析、仿真和正交实验结果对微阀结构参数进行了优化。实验结果表明,通道高度和宽度对泄漏率影响最大,通道高度对开启率影响最大。获得最优开闭性能的结构参数组合为:通道宽度1 mm,高度0.1 mm,底膜厚度0.2 mm,顶膜厚度0.2mm,电磁机构压力3×104 Pa。基于该结构参数组合的微阀在10kPa内可以实现零泄漏及近似完全开启。该阀具有易与微流控芯片集成、低电压驱动、制作简单、无死体积等优点。     

多级低压电渗流微泵的设计、加工及测试

设计了一种多级低压电渗流微泵.该微泵系统主要由直流电源和蚀刻微通道的芯片等部分组成.芯片是在一块硅基片上蚀刻6组尺寸不同的微通道,从而达到提供不同大小的流量和承受不同背压的目的.对芯片的加工工艺流程进行了说明,同时对微泵进行了试验研究.实验结果表明:在低压下,该泵能够驱动通道中的液体.     

多级低压电渗流微泵的设计、加工及测试

设计了一种多级低压电渗流微泵。该微泵系统主要由直流电源和蚀刻微通道的芯片等部分组成。芯片是在一块硅基片上蚀刻6组尺寸不同的微通道,从而达到提供不同大小的流量和承受不同背压的目的。对芯片的加工工艺流程进行了说明,同时对微泵进行了试验研究。实验结果表明：在低压下,该泵能够驱动通道中的液体。     

Design and operation of a portable scanner for high performance microchip capillary array electrophoresis

We have developed a compact, laser-induced fluorescence detection scanner, the multichannel capillary array electrophoresis portable scanner (McCAEPs) as a platform for electrophoretic detection and control of high-throughput, integrated microfluidic devices for genetic and other analyses. The instrument contains a confocal optical system with a rotary objective for detecting four different fluorescence signals, a pneumatic system consisting of two pressure/vacuum pumps and 28 individual addressable solenoid valves for control of on-chip microvalves and micropumps, four Polymerase Chain Reaction (PCR) temperature control systems, and four high voltage power supplies for electrophoresis. The detection limit of the instrument is ~20 pM for on-chip capillary electrophoresis of fluorescein dyes. To demonstrate the system performance for forensic short tandem repeat (STR) analysis, two experiments were conducted: (i) electrophoretic separation and detection of STR samples on a 96-lane microfabricated capillary array electrophoresis microchip. Fully resolved PowerPlex(?) 16 STR profiles amplified from 1 ng of 9947A female standard DNA were successfully obtained; (ii) nine-plex STR amplification, sample injection, separation, and fluorescence detection of 100-copy 9948 male standard DNA in a single integrated PCR- capillary electrophoresis microchip. These results demonstrate that the McCAEPs can be used as a versatile control and detection instrument that operates integrated microfluidic devices for high-performance forensic human identification.     

Motion video image processing (MVIP) method for measuring microfluidic–structure interactions

In microsystem applications, many microstructures are submerged in fluid and their performances are directly influenced by the microfluidic–structure interactions. Characterizations of such interactions in microfluidic devices such as micropumps, microvalves, micro-viscometers, and biomedical related microfluidic chips, are essential to seek enhanced designs and design guidance. In this study, a hybrid microfluidic test chip with integrated microcantilever is fabricated on a polymer platform using soft lithography method for characterization of microcantilever–fluid interactions. A measurement technique based on the motion video image capture and processing (MVIP) is developed to measure the static and dynamic deflections of the microcantilever subjected to forces due to fluid within the microchannel. A peristaltic pump was used to generate fluid flows across the channel, which caused a pressure differential loading of the microstructure. The images of motion were processed to characterize the motion in terms of deflection, velocity and acceleration of the structure under different flow conditions. The validity of the proposed MIP method is illustrated through comparisons with finite element model of the microcantilever. The images acquired from the proposed MVIP method were further analyzed to estimate deflection mode shapes and natural frequencies of the microcantilever under fluid interactions.     

液相色谱-质谱用于代谢标志物的发现和鉴定

代谢组学是测量相对分子质量1 000以下的内源性代谢物的科学,目前已在疾病研究、药物研发及植物和微生物等领域均得到重视,是研究小分子的一个十分有用的工具。它以组织、体液或细胞为研究对象,最常用的技术是质谱和NMR。一般来说,代谢组学的研究包括样品采集、预处理、代谢组数据采集、多变量数据分析、标志物发现和识别及最终的生物解释。由于缺乏数据库及标样,代谢标志物的识别是研究的一个瓶颈。 在这里,我们将报告一个基于色谱-质谱联用技术的集成识别策略,包括多变量数据分析、精确分子量测定、质谱碎片裂解规律、色谱保留规律、馏分微制备、亲和色谱、酶解等。 药物作用机理和疾病标志物的代谢组学研究将作为例子阐明我们的策略。     

Building Open CNC Systems with Software IC Chips Based on Software Reuse

Based on the concept of software reuse, this paper discusses the feasibility and necessity of developing CNC software IC (SIC) chips and proposes a methodology for building new CNC systems using multiple SIC chips. A SIC chip is an integrated program to execute certain functions in CNC systems. Different SIC chips can be integrated to build a new CNC system for special system requirements. In this paper, the interactive information among different SIC chips is analysed, and related specifications for information exchange are suggested. In addition, a procedure for developing a SIC chip for NC code interpretation is described and its role in building a CNC system is discussed. Lastly, an integrated development platform is presented for building an open CNC system with SIC chips.     

微流控芯片发展与展望

介绍了微控分析系统的一般特点,发展历史和近期的研究进展,分别讨论了微流控分析系统中有关流控系统,芯片材料,检测系统,集成化系统,分离系统,试样引入和前处理系统等研究领域的发展趋势,并对微流控分析系统的应用前景做出了展望。     

基于数控机床自动排屑过滤系统的技术研究

在绿色制造技术的大环境下,对数控加工中切屑的收集、切削液的回收处理再利用以及排屑系统的智能检测控制进行了研究,通过多级过滤、油水分离、智能控制等手段对系统平台进行了技术攻关,研制了一种集成化、低成本、高控制精度,能用于各种不同加工环境的自动排屑过滤系统,提高了排屑过滤效率,节约了切削液。     

基于SoC的便携式智能光度分析仪的研制

介绍了一种基于片上系统SoC的便携式智能光度分析仪。仪器以C8051F005芯片为核心，通过充分利用SoC片内的12位模／数转换器ADC、可编程计数器阵列PCA、Flash存贮器和UART接口等硬件资源，实现了多通道独立计时测量、非易失性数据存贮、串口数据输出与打印等功能，即减少了仪器的外围芯片数量，又缩短了开发周期。与传统的板上系统相比，该仪器具有结构简单、可靠性高、功耗小、价格低等特点。配合相应波长的LED单色光源与化学试剂包，在该分析仪上实现了COD、氨氮、磷酸盐、甲醛、农药残留等多种水质与食品安全检测指标的现场快速测量。     

某宇航相控阵天线振动故障分析

文中针对某宇航相控阵天线在随机振动验收试验过程中的振动故障,首先通过罗列故障树和摸底试验进行故障定位,分析认为DSP芯片引脚在振动过程中应力过大是造成其开裂的主要原因;然后通过有限元法计算试验条件下DSP芯片引脚处的加速度和应力响应,仿真结果与试验结果比较一致;最后根据有限元模型开展相控阵天线主结构的优化设计,增加主结...     

Experimental investigation on chip morphologies in high-speed dry milling of titanium alloy Ti-6Al-4V

An experimental investigation of chip morphologies in high-speed dry milling of Ti-6Al-4V alloy was conducted over a variety of different cutting conditions. Observation on the multi-view characterization of the chips was carried out which includes free surface, back surface, and cross-section of top surface. Structure and shape alterations of the free and back surfaces were analyzed using an optical microscope and a scanning electron microscope (SEM). The microstructural analysis indicated that the chip morphology when dry milling Ti-6Al-4V alloy in high-speed range exhibited a serrated shape for a wide range of cutting conditions. The degree of chip serration is more pronounced and evident with the increase in cutting speed, feed, and depth of cut. A significant variation in the microstructure of the chip including the thickness of the shear bands and the serrated tooth structure for different cutting speeds has been identified. The higher chip serration ratio (CSR) in high cutting speed range may facilitate appropriate machining condition for the occurrence of well-broken chips. Moreover, chip formation takes place by the mechanism of catastrophic thermoplastic shear from the observation of the shear bands using metallurgical analysis techniques. X-ray diffraction results indicated that no evidence of phase transformation was found in the shear localized chips. The variation in chip serration and metallurgical microstructure inside the shear bands and the tool/chip contact zone should be attributed to the reinforcement of coupled thermo-mechanical behavior in the cutting process with the increase in machining parameters.