基于介电泳的细胞介电参数测试芯片机理的数值分析

设计一种集成四极式微电极组和螺旋微电极组的介电泳(Dielectrophoresis, DEP)细胞介电参数测试芯片,在芯片上集成了细胞的常规介电泳(Conventional DEP, CDEP)、行波介电泳(Travelling-wave DEP, TWDEP)和电旋转介电泳(Electrorotation, EROT)测试功能。运用相量法建立交流电场中细胞所受的常规介电泳力、行波介电泳力和介电泳旋转转矩的计算模型,推导出细胞水平速度和自旋角速度的表达式,并对本芯片的CDEP因子、TWDEP因子及EROT因子的大小和方向及细胞运动速度进行数值模拟并结合文献中的试验数据进行对比论证。结果表明：在高度大于20 m的区域,细胞沿螺旋电极径向的行进速度与细胞有效极化率的实部和虚部都相关,而细胞悬浮高度仅与有效极化率的实部相关;另一方面,电旋转最佳测试区域为近似正方形区域且每条边的中点均处于邻近的电极顶尖与电极腔中心连线的中点之上,此区域内的介电泳转矩变化量小于5%且介电泳力最小,利于电旋转测量。因此,本测试芯片能够通过多种介电泳模式更为全面、准确地获取细胞的介电特性信息。     

基于SoPC的行波介电电泳芯片控制与采集平台设计

介绍了一种利用SoPC技术控制与采集行波介电电泳芯片的方案.以嵌入在FPGA(CyelonⅡ EP2C35)中的RISC结构的CPU软核NiosⅡ为基础,通过FPGA的DSP开发工具DSP Builder对直接数字频率合成器(DDS)进行建模,在QuartusⅡ软件中生成DDS IP核,控制输出4路相位严格相差90°的正弦波,建立行波电场驱动不带电生物粒子定向移动,实现不同生物粒子的分离;采用自定制I2C模块,实现300万像素CMOS图像传感器MT9T001的配置,完成不带电生物粒子的非接触检测.文中重点介绍了基于DSP Builder的DDS IP核设计,自定制I2C模块以及系统软、硬件设计,并通过仿真分析证明了这种设计方法的正确性和实用性.     

Effects of chip geometries on dielectrophoresis and electrorotation investigation

The electric fields employed for such work are generated using chips, such as planar linear interdigitated arrays or two parallel arrays. However, chip geometries usually affect the investigation of dielectrophoresis （DEP） and electrorotation （ER） significantly, and even may misdirect the theoretical prediction. In order to understand the electrodes geometries effect and provide a suitable range of parameters, three-dimensional simulations for the DEP and ER characterizations on the quadrupolar hyperbolical electrodes are carried out. Influences of the electrodes gaps, cell height, work region, energized voltage and frequencies for the DEP and ER manipulations are analyzed, and the analysis results show that the gaps of the electrodes and the cell height have enormous effects, but the work region is not so important. Moreover, depending on the theoretical analysis, ER experiments for polystyrene microspheres with the diameter of 20 ~m are carried out on two kinds of chips. The experimental results show that the microspheres rotate in the counter-field direction and the maximum rotation speed appears in the megahertz range. In addition, the experimental results are compared with the simulation results, showing that the three-dimensional simulations considering the chip geometries are more accurate than the two-dimensional predictions. This paper provides a new understanding for the theoretical predictions of DEP and ER manipulations, which decreases the difference of the theoretical and experimental results significantly, and will be significant for the lab chip research.     

基因芯片技术在生命科学研究中的应用进展及前景分析

目的：探讨生命科学研究领域基因芯片技术研究现状及未来的应用前景。方法：收集有关基因芯片技术在生命科学研究中的国内外研究资料并加以综合归纳。结果：基因芯片技术是一种高新生物技术,因具有高通量、并行性、微型化与自动化等特点,在生命科学中日益显示出其重要的理论与实际应用价值。结论：基因芯片技术在生命科学领域的深入研究具有重要的理论意义和应用价值,前景广阔。     

电子封装金属微凸点制备技术研究进展

起着电互连、热传递和机械支撑等重要作用的金属微凸点是基于面积阵列封装的关键。以球栅阵列封装（Ball Grid Array Packaging, BGA）、芯片尺度封装（Chip Scale Packaging, CSP）以及倒装芯片封装（Flip Chip Packaging, FCP）为代表的面积阵列封装形式凭借硅片利用率高、互连路径短、信号传输延时短以及寄生参数小等优点迅速成为当今中高端芯片封装领域的主流。然而,不同应用领域的微凸点具有尺寸跨度大、材料范围广的特点,很难有一种技术能实现全尺寸范围内不同材料金属微凸点的制备。文中综述了当前主流的微凸点制备技术,包括每种技术的优缺点及其适用范围、常见微凸点材料等,最后对当下微凸点制备技术的发展趋势进行了展望。     

Toxicogenomic analysis of gene expression changes in human liver cells after exposure to environmentally friendly lubricants

A lubricant based on synthetic esters and a mixture of this lubricant with additives and metals simulating the intake caused by usage were investigated with various ecotoxicological and genotoxicological tests. Tests with algae, daphnids and bacteria demonstrated an influence of the mixture on ecotoxicity. The genotoxicity tests, however, showed no effects for both samples. In addition, genetic effects were examined in detail by using gene expression profiles of HepG2 cells. Comparison of the set of regulated genes for early and late time points indicated a certain concordance between the genes up‐regulated after 6 and 24 hours of exposure. The correlation for the corresponding down‐regulated gene groups is slightly lower. Generally, the number of regulated genes is low (3–6%) demonstrating a marginal influence. The results indicate that the assessment of gene expression profiles, in addition to the quantification of toxic effects, may give important information on ways of toxic action of a substance. These data can be used in the development of new chemicals or products in order to minimize toxic effects. Copyright © 2007 John Wiley & Sons, Ltd.     

一种高效率低成本制作微透镜阵列的方法

通常采用的多次掩模光刻和离子束刻蚀制作微透镜阵列的方法不但制作效率低,而且易产生较大的制作误差。提出了一种在硅基底聚合物薄膜上热压制作微透镜阵列的工艺方法,并利用自制的热压印设备进行了热压制作衍射微透镜阵列的试验,讨论了影响压印精度的温度和压力等工艺参数,对压印的衍射微透镜阵列进行了轮廓测试和部分光学性能测试。测试结果表明,压印制作微透镜阵列的复形误差小于10%,衍射效率高于90%,为高效率低成本制作微透镜阵列提供了一种新的方法。