一种聚合物平板微器件的制造方法

以一种平板微器件-微流控芯片制造为研究对象,针对单一的注塑成型工艺难以保证器件的宏微形位误差的难题,提出了一种新颖的聚合物平板微器件集成制造方法。首先,设计并制造了一套注塑模具,其中采用双螺纹结构将微镶件和定模架相连,对注塑工艺参数进行优化,制得填充率接近1的平板微制件。然后,对平板微制件进行了基于视觉对准的铣削整形和热压整平,有效改善了制件的宏微形位误差和平面度误差。最后,利用加工的器件进行装配,形成微流控芯片,并对芯片进行了流量测试和疲劳测试。实验结果表明:采用提出方法制造的微流控芯片,各项精度指标和性能可以满足实际使用要求,工艺成果对同类器件的研发和生产提供了借鉴和指导。     

PMMA微流控芯片微通道热压成形与键合工艺研究

微流控芯片在化学分析、临床诊断等领域的应用前景广阔.聚合物材料具有低成本、良好的加工性能、可用热压等快速成形方法加工微通道、易于实现批量生产等优点,适于作为制作微流控芯片的基材.本文研究了微通道热压成形及其芯片制作工艺.以聚甲基丙烯酸甲酯(PMMA)为基材制作了微流控芯片.在加热软化的PMMA上,用带有凸起微结构的镍模具在基片上压制出开放微通道,讨论了热压过程中温度、压力对芯片微通道成形质量的影响,确立了优化的热压成形工艺.在PMMA玻璃转化点(Tg)附近,通过施加一定的压力,实现基片与盖片的直接键合,获得了密闭分离微通道,并在PMMA微流控芯片上实现了安非他明的分离检测.     

聚合物微流控芯片激光加工及建模研究

在CO2激光直写聚合物PMMA微流控芯片加工原理基础上，对建立激光直写PMMA微流道的数学模型进行了研究。采用能量守恒原理对激光直写PMMA微流道成形进行分析，结果表明其微流道的形状呈高斯函数型分布，并获得了微流道深度与激光功率、加工速度及加工次数的函数关系模型。实验数据较好地验证了所建模型的正确性，该模型对CO2激光直写聚合物微流控芯片的加工参数选择具有较好的指导作用。     

PC微流控芯片黏接筋与溶剂的协同辅助键合

为了在微流控芯片上形成封闭的微通道等功能单元,克服热压键合中微流控结构的塌陷和热压所致芯片微翘曲对后续键合的影响,提出了一种适用于硬质聚合物微流控芯片的黏接筋与溶剂协同辅助的键合方法。以聚碳酸酯(PC)微流控芯片为研究对象,通过热压法在PC微流控芯片上的微通道两侧制作凸起的黏接筋,通过化学溶剂丙酮微溶PC圆片的表面,然后将PC圆片与带有黏接筋的PC微流控芯片贴合、加压、加热,从而实现微流控芯片的键合。分析了键合机理,并对键合工艺参数进行了优化。实验结果表明:键合质量受丙酮溶剂溶解PC圆片的时间和键合温度的影响,能够保证键合质量的最佳键合温度为80~90°,溶解时间为35~45s,芯片的键合总耗时为3min。与已有键合工艺相比,所提出的黏接筋与溶剂辅助键合工艺有效提高了键合效率。该键合方法不仅适用于具有不同宽度尺寸微通道的微流控芯片,还可扩展用于不同材料的硬质聚合物微流控芯片。     

微流控芯片的键合技术与方法

键合是将组成微流控芯片的基片和盖片以某种方式结合在一起,从而形成封闭的微通道的一种装配方法。键合质量直接影响到微通道中流体的运动形态,从而影响检测效果,因此键合是微流控芯片制作过程中非常重要的环节。综述了现有的微流控芯片键合技术和方法,分析了各种键合技术和方法在键合质量、键合效率以及操作简便性等方面的特点,为不同材质、不同应用领域的微流控芯片选择适用的键合方法提供了技术指南,对键合技术的未来发展进行了分析和预测。     

CO2激光直写加工PMMA微流控芯片

提出使用CO2激光器进行PMMA微流控芯片加工的方法.研究了激光功率,频率,扫描速度等参数及加工程序对芯片加工质量的影响.使用热压法进行芯片键合.考察了键合过程交叉沟道局部封闭的原因并提出工艺的改进.采用三维显微成像系统和配置CCD的金相显微镜对PMMA芯片的微沟道及其横截面进行了表征.该方法快速简单,设备成本和操作成本低廉,尤其适于科研机构进行芯片的前期开发.     

一种新型微流控芯片金属热压模具的制作工艺研究

研究了利用UV-LIGA技术制造PMMA微流控芯片金属热压模具。采用预机械抛光的Ni板作为电铸基底,光刻SU-8 2050后形成电铸型模,然后电铸Ni微通道,去胶后电铸基底与微通道结合形成芯片热压模具。此方法有效地解决了传统UV-LIGA方法中的倒拔模斜度的问题。制作的微流控芯片模具微通道的宽度和高度尺寸偏差分别为1.7%和2.8%,满足微流控芯片的应用要求。     

微流控芯片光学检测系统集成化新进展

微流控芯片是微全分析系统(μTAS)中当前最活跃的领域和发展前沿。目前人们在微流控芯片的研究中已经取得了很大的进展,研制出了多种微型化、集成化的芯片。相比之下,与微流控芯片配套的高灵敏度微型光学检测系统的研制却相对落后。介绍了分别基于CMOS、垂直腔面发射激光器(VCSEL)和微型雪崩光电二极管(μAPD)来实现光学检测系统与微流控芯片集成化的方法。     

微流控芯片二维电泳分离分析系统研究进展

微流控芯片分析系统(微全分析系统)近年来发展迅速,已经被应用于生物、环境样品的分离分析研究。多维分析系统能够极大地提高峰容量,适合于复杂样品体系的分离分析。在微流控芯片上进行的分离操作不仅可以有效地实现两种分离模式之间的零死体积切换,而且能够使分析速度与峰容量的矛盾得到补偿。本文对微流控芯片二维电泳分离分析系统的近期发展作综述,并展望其可能的发展前景。     

声操控型微流控芯片的加工与测试技术

介绍了一种声操控型微流控芯片的加工方法与测试技术。首先,基于声操控型微流控芯片的工作原理和功能需求设计了硬质微流控芯片的基本结构,采用激光切割方法实现了聚甲基丙烯酸甲酯（polymethylmethacrylate,简称PMMA）材质开放边界微流道的加工,采用数控加工（computerized numerical control,简称CNC）精雕方法实现了封闭边界微流道的加工,通过光固化型（ultra violet,简称UV）胶实现了硬质微流道与基板的室温封接,利用表面改性技术与毛细作用实现了芯片的无泵进样;其次,研究了不同加工工艺、工艺参数对微流道形貌的影响;最后,依据声操控微颗粒需求,综合仿真分析、阻抗测试及多普勒激光测振,选定了声操控型微流控芯片的工作频率,实现了微纳物体运动控制。该微流控芯片具有成本低、加工效率高及易于调整微流道结构的优点,在微纳操控、微纳制造和生化检测方面拥有广阔的应用前景。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.