一种非硅微加工技术制作的电热微驱动器

介绍了一种由非硅微加工技术制作的电热微驱动器。基于双金属效应,采用聚合物SU-8胶和金属镍作为功能材料和结构材料,铜为牺牲层材料制作电热微驱动器。利用ANSYS有限元分析软件进行仿真,模拟驱动位移随加热时间的变化关系,并由此得出驱动力的大小,比较结果后确定结构参数。再通过光刻、掩模电镀和牺牲层刻蚀等工艺,加工制作出了电热微驱动器样品,并对样品进行了观测和分析。     

1×16微机电系统光纤连接器阵列的研制

一种基于MEMS工艺的硅基阵列化光纤连接器,具有微型化、可集成制造和重复性好等特点。每个单元利用硅V型槽与其上集成制造的电沉积流线型曲面金属镍盖板的组合形成了方便光纤插拔的喇叭口形导引通道和可实现光纤定位及精确自对准的双悬臂梁形夹持通道。采用Ansys软件对双悬臂梁结构在不同的厚度与翘曲位移条件下对光纤产生的压制力进行建模与仿真,并将其与理论分析结果进行比较。成功地将单元扩展成1×16阵列,体积仅为6.8mm×15.2mm×0.5mm,各单元插入损耗约为0.3 dB。     

1×16微机电系统光纤连接器阵列的研制

一种基于MEMS工艺的硅基阵列化光纤连接器，具有微型化、可集成制造和重复性好等特点。每个单元利用硅V型槽与其上集成制造的电沉积流线型曲面金属镍盖板的组合形成了方便光纤插拔的喇叭口形导引通道和可实现光纤定位及精确自对准的双悬臂梁形夹持通道。采用Ansys软件对双悬臂梁结构在不同的厚度与翘曲位移条件下对光纤产生的压制力进行建模与仿真，并将其与理论分析结果进行比较。成功地将单元扩展成1×16阵列，体积仅为6．8mm×15．2mm×0．5mm，各单元插入损耗约为0．3dB。     

新型复合结构电热微驱动器的研制

在弯曲梁电热微驱动器原理的基础上,通过引入热膨胀系数更大的聚合物,提出了一种新型复合结构电热微驱动器。采用了ANSYS有限元分析软件,对其基本结构形式进行了系统的仿真分析,得到了一组初步优化的器件结构参数。仿真结果表明:新型电热微驱动器有更低的能耗和更大的位移。采用非硅表面微加工技术,成功制备了新型复合结构电热微驱动器。     

罩式退火炉计算机控制的数学模型

退火是矽钢片生产过程中十分关键的一个工艺环节,实践证明,退火工艺的执行情况直接影响到矽钢片的电磁性能(牌号)和翘曲度质量。上海矽钢片厂是利用电热罩式炉来进行退火生产的,退火炉的结构如图(1)所示     

一种新型的电热驱动MEMS微继电器的研制

设计和制备了一种新型的电热驱动微电子机械(MEMS)继电器,并进行了性能测试.整个工艺采用非硅MEMS工艺,利用Cu作为牺牲层材料,Ni作为微继电器的结构材料.微继电器是基于杠杆放大原理设计的,因此能够获得较大的行程;驱动臂采用"U"型梁设计,能够在不增加功耗的条件下,获得较大的驱动力.并采用Ansys10.0有限元软件对微继电器进行了模拟分析.测试结果表明,这种微型继电器具有体积小、驱动电压低、切换速度快等优点.     

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。     

空芯光子带隙光纤在光纤陀螺中的应用前景

光纤是光纤陀螺的核心器件之一。光纤的性能参数直接决定光纤陀螺的性能。常规硅芯光纤制造工艺比较成熟,但受限于物理条件,＂克尔效应＂、＂瑞利背向散射效应＂、＂法拉第效应＂和＂舒珀效应＂影响比较大。近年来,基于光子带隙效应的导光机制与传输特性制成的在空气中传输光线的空芯光子带隙光纤逐渐应用在光纤陀螺制造中。介绍空芯光子带隙光纤的性能特点,尤其是相比常规硅芯光纤的优势;空芯光子带隙光纤的技术发展潜力;展望其在光纤陀螺中的应用前景。     

用于硅基氮化镓可调微镜的静电梳齿型微驱动器设计

提出并设计了一种用于硅基氮化镓(GaN)可调微镜的静电梳齿型微驱动器.利用有限元软件建立了该器件的几何结构模型,对器件的结构进行了仿真优化.此外,采用微机电系统(MEMS)加工工艺,制作出了用于硅基氮化镓可调微镜的梳齿型微驱动器,并对其驱动特性进行测试.测试结果表明:所制作的微驱动器的位移随着电压的变化呈二次方关系,与仿真结果基本一致.当加载驱动电压为200 V时,微驱动器的驱动位移可达到1.08 μm.     

电热循环次数对光纤传感器封装材料的耐久性试验研究

针对电热循环次数对光纤耐久性的影响,选取英国进口光纤,采用循环通电加热光纤金属铠的室内试验,获得了不同电热循环次数下光纤的拉力-位移曲线,得到不同电热循环次数下光纤金属铠最大抗拉力;分析了光纤极限抗拉力-加热循环次数关系,得到光纤金属铠耐久性推算公式.研究结果表明:随着电热循环次数的增加,光纤金属铠最大抗拉力不断减少且减少的速度越来越快.研究结果对相应工程合理选择与之耐久性相适应的传感光纤有重要的指导意义.     

基于蜂窝结构的传感器网络覆盖问题求解算法

在无线传感器网络中,求解能够完全覆盖目标区域的最小覆盖集是个NP难问题.在传感器节点数目较多时,目前只能通过近似算法求解.蜂窝结构是覆盖二维平面的最佳拓扑结构,但不能直接用于求解无线传感器网络的覆盖问题.提出了一种基于蜂窝结构的覆盖问题求解算法,在该算法迭代求解过程的每一阶段,选出一个节点加入到初始为空的节点集合中,并使得该节点集合的拓扑结构接近于蜂窝结构,直至该节点集合成为覆盖集.该算法在最坏情况下的时间复杂度为O(n3),这里n为传感器节点总数.实验结果表明该算法可在很短的时间内执行完,在所得覆盖集的大小方面要优于现有的覆盖问题求解算法.     

Plasma assisted thermal bonding for PMMA microfluidic chips with integrated metal microelectrodes

Fracture of integrated metal microelectrodes likely happens during the thermal bonding process of PMMA [poly (methylmethacrylate)] microfluidic chips. In this paper, the fracture behaviors are studied. The fracture is mainly caused by the plastic deformation of the electrode plate (the PMMA plate with microelectrodes) and the thermal stress of microelectrodes, which is due to the high bonding temperature. To decrease the bonding temperature, a plasma assisted thermal bonding method is evaluated and first used to eliminate the fracture of microelectrodes. In this process, the surface of the cover plate (the PMMA plate with microchannels) is modified using oxygen plasma before the electrode plate is thermally bonded to the cover plate. The parameters of the oxygen plasma treatment are optimized, and the contact angle is decreased from 71.7° to 43.6°. The thermal bonding temperature is optimized, which decreases the temperature from 100 °C to 85 °C. Testing of bonding strength shows an average failure pressure of 1.75 MPa, which is comparable to the bonding strength of 1.46 MPa for chips bonded at 100 °C without plasma modification. In order to demonstrate this bonding method, a PMMA microfluidic chip with integrated copper interdigitated microelectrode arrays for AC electroosmotic pump is fabricated.     

多变量自适应极点配置的递推算法

本文提出一个递推计算控制器参的方法，得到具有两层迭代过程的多变量自适应极点配置算法，大幅度减少了在线计算量，同时在辩识算法中利用投影方法，证明了该算法的稳定性和收敛性。     

热辐射型光纤高温传感器及其性能研究

介绍了一种光纤高温传感器及其测温原理和测量方法,研究了传感器的设计结构、稳定性、一致性和互换性等。系统根据黑体热辐射原理,采用双波长比色测温法和光纤传感技术来实现准确测温。结果表明:"接触—非接触"式的测温结构避免了光纤直接接触高温源,传输光功率衰减对传感器测量精度的无影响,传感器具有很好的一致性,完全可以互换使用,也可实现高温高压设备中的温度测量。     

Constructing the dependency structure of a multiagent probabilisticnetwork

A probabilistic network consists of a dependency structure and corresponding probability tables. The dependency structure is a graphical representation of the conditional independencies that are known to hold in the problem domain. We propose an automated process for constructing the combined dependency structure of a multiagent probabilistic network. Each domain expert supplies any known conditional independency information and not necessarily an explicit dependency structure. Our method determines a succinct representation of all the supplied independency information called a minimal cover. This process involves detecting all inconsistent information and removing all redundant information. A unique dependency structure of the multiagent probabilistic network can be constructed directly from this minimal cover. The main result is that the constructed dependency structure is a perfect-map of the minimal cover. That is, every probabilistic conditional independency logically implied by the minimal cover can be inferred from the dependency structure and every probabilistic conditional independency inferred from the dependency structure is logically implied by the minimal cover     

Large-strain thermo-mechanical behavior of cyclic olefin copolymers: Application to hot embossing and thermal bonding for the fabrication of microfluidic devices

Amorphous cyclic olefin copolymers (COCs) are beginning to be used for making microfluidic devices for life science applications. Typically, both micro-scale and nano-scale channels are imprinted onto the copolymer by hot embossing. However, optimal manufacturing process conditions will only be possible if the COCs thermo-mechanical behavior is experimentally well characterized, mathematically modeled, and implemented in a numerical simulation. We have conducted large-strain compression experiments on two commercial grades of COCs: TOPAS-8007, and TOPAS-6015 in a wide temperature, and strain rate range. A constitutive theory and numerical implementation developed by Srivastava et al. [1] was applied to model the behavior of TOPAS. We have employed that numerical implementation, together with the material parameters for TOPAS determined here, to predict the response of TOPAS in the following microfluidic fabrication operations: (i) micro-scale hot embossing on TOPAS-8007 to replicate a micro-chip; and (ii) for sealing the channels in the micro-chip: (a) thermal bonding of an embossed chip of TOPAS-8007 with a cover plate of TOPAS-8007; and (b) thermal bonding of an embossed chip of TOPAS-6015 with a cover plate of TOPAS-8007. We show that the model can provide a simulation capability for estimation of the processing parameters for hot embossing and thermal bonding.     

三轴一体IMU组件中光纤环热分析

对某型号三轴一体光纤陀螺捷联惯导系统建立有限元模型,从结构角度分析了惯性测量单元（ IMU）中光源和加速度计等发热模块对光纤环温度场分布的影响。分析研究IMU组件在22℃常温稳态下的传热规律,表明光源与加速度计等热源所产生热量将不以传导方式在箱体与 IMU台体之间传递,对流与辐射传热对IMU温度分布影响较大;光源为主要热源,是造成Y,Z轴光纤环温度分布不均匀的主要原因;加速度计发热将影响X轴光纤环温度分布。通过＋60℃高温瞬态热分析,研究光纤环在极端环境下温度变化规律,表明系统在极端环境下随着温度上升而温度梯度递减,光纤环瞬态温差增大。稳态和瞬态热分析可指导惯导系统IMU部分结构热设计的改进。     

Study of TBM cutterhead fatigue crack propagation life based on multi-degree of freedom coupling system dynamics

Cutterhead is the core component of TBM tunneling equipment, which endures strong, multi-point distributed impact loads when the TBM tunnels, owing to the extreme surrounding rock environment of high hardness, high temperature and high quartz content. For this reason, the cutterhead works in an extremely severe vibration environment, which leads to engineering fault by a large area crack damage before the service life. Hence, the study on life prediction of TBM cutterhead under the impact loads is a core part of cutterhead design. This paper combines with the technology of system dynamics, linear elastic fracture mechanics and cumulative theory of fatigue damage, for the first time, proposes a method of fatigue crack propagation life prediction for the large and complex structures. In this paper, the TBM cutterhead of an actual project is taken as an example, to predict the fatigue crack propagation life of cutterhead piece and analyze the influences of plate thicknesses on fatigue life, then a new improved scheme of cutterhead structure is presented. The results show that the fatigue crack propagation life of actual cutterhead is 26.6 km, which is able to meet the requirement of 20 km service life. Moreover, the upper cover plate thickness has the greatest influence on cutterhead fatigue crack propagation life, with the thickness increasing 10%, the life increases nearly by 1.24 times. Then, the other influencing factors are as follows: thickness of the main support plate, thickness of the annular support plate and thickness of the support plate, whereas the influence of the lower cover plate thickness on fatigue life is minimal. Furthermore, the plate thickness limit sizes meeting the life requirement are obtained, and a new structure modified scheme of cutterhead is proposed. Compared with the original scheme, the new cutterhead scheme meets the requirements of structural strength and service life with 8.08% weight decrease, which achieves life determination design and lightweight design. The proposed method of fatigue crack propagation life prediction is feasible in the design and application stage of TBM cutterhead, besides, it is flexible enough and can also be applied in damage strength assessment, dynamic parameters optimization and establishment of nondestructive inspection cycle for the other large and complex structure, and takes on stronger project value and generality.     

干涉型光纤温度传感器

为了长期和在线实时检测各种工程结构内(如飞机机翼)的温度,在介绍了2种典型的干涉型光纤温度传感器技术的基本原理、结构及优缺点的基础上,提出了一种新型光纤温度传感器——嵌入式干涉型光纤温度传感器的工作原理和结构设计。它用特殊加工工艺将光纤埋入材料中,通过相位调制产生干涉条纹,再通过条纹的判向计数来对材料内部温度进行测量。实验结果表明:嵌入式光纤温度传感器能长期有效测量材料内部的温度,并且,它的灵敏度比放在空气中的灵敏度要高2~3倍。具有很大的研究开发和应用价值。     

基于行人头部保护和刚度要求的发动机罩内板优化设计

提出一种基于行人头部保护和刚度要求的汽车发动机罩内板优化设计方法,将其应用于某款发动机罩内板的参数化设计和优化分析.对优化方案与初始方案的行人头部碰撞仿真结果进行对比,结果表明:优化方案在满足发动机罩刚度要求的前提下能显著降低行人头部碰撞的伤害值.该优化方法可行,可为发动机罩内板的优化设计提供参考.