形状记忆合金/硅复合膜驱动的微泵

形状记忆合金／硅复合膜驱动的微泵由一个可形变腔体和两个单向硅薄片阀组成，微驱动膜利用ＮｉＴｉ形状记忆合金薄膜相变时具有大的可回复应力和Ｓｉ衬底膜的反偏置力，产生双向往复振动，采用图形化的ＮｉＴｉ薄膜作为热诱发相变的加热电阻，有效地提高了动态响应频率。同时降低了驱动功率。通过驱动结构的优化设计。增加了驱动位移和工作寿命。微泵采用Ｓｉ表面和立体微加工工艺、金－硅共晶键合等技术制备，它的外形尺寸为６ｍｍ     

新型的形状记忆合金／硅薄膜微驱动器

介绍了一种用硅微加工技术制作的ＮｉＴｉ／Ｓｉ 薄膜结构的双向微驱动器。它利用ＮｉＴｉ 形状记忆合金薄膜（ＳＭＡ） 大的相变回复应力和Ｓｉ 衬底膜的反偏置力产生有一定位移量的双向运动。对ＮｉＴｉ 薄膜进行合理的图形化后使得驱动器位移量增大,双向效应显著,响应速度提高。同时图形化后的ＮｉＴｉ 膜也是加热电阻,使驱动结构简单,所需功率减少。驱动器实际驱动面积为３ ×３ｍ ｍ２ 厚度为２０μｍ 。可产生的最大位移为５０μｍ ,最高驱动频率可达１００Ｈｚ。驱动功率可减小到２００ｍ Ｗ。经过１０００ 万次振动后,驱动膜无开裂,性能正常。它已被成功的应用于压缩型微泵,该泵最大流量达３４０μＬ／ｍｉｎ 。     

压电微泵的特性测试与分析

本文对压电驱动微泵的工作特性进行了系统测试，利用高压方波信号源产生频率和电压可调的信号来驱动微泵，采用高精度电子秤测量固定时间(10s)内微泵输送液体的质量大小，并对工作特性进行相关分析，总结了压电微泵的输送流量随液体黏度、驱动电压和驱动频率之间的关系。结果表明，在相同的驱动条件下，液体黏度越大，压电微泵输送的流量越小，在固定的驱动电压下，当驱动频率为泵膜的谐振频率时压电微泵输送的流量最大，高于或低于驱动频率时输送的流量越来越小，在固定的驱动频率下(谐振频率)，压电微泵输送的流量随驱动电压的升高而增加。研究结果为压电微泵的优化设计和实际应用提供了依据。     

无阀压电微泵的动态特性研究

微泵作为微流控系统中的核心控制元件已成为MEMS研究的热点，现主要研究了无阀式压电微泵的工作原理及其动态工作特性。实验表明，无阀压电微泵的流速随频率呈抛物线关系变化，最佳工作频率为1250Hz。在频率固定时，微泵流速随驱动电压的升高而增加。泵膜的厚度对于微泵的性能影响很大，相同条件下，较薄的泵膜具有更高的流速，且泵膜越薄，其性能对于频率的变化越敏感。电压为50V时，微泵最大流量可达1．695μL/min。总体看来，无阀压电微泵结构简单，驱动电压较低，性能稳定可靠。     

PZT压电薄膜无阀微泵的制备工艺及实验研究

介绍了一种基于PZT薄膜的无阀压电微泵。该微泵利用聚二甲基硅氧烷(PDMS)作为泵膜,自制的压电圆型薄膜片作为驱动部件,采用收缩管/扩张管结构,压电圆型致动片和PDMS泵膜的组合可产生较大的泵腔体积改变。在对微泵制备工艺研究的基础上,对其性能进行了实验研究,结果表明:电压和频率对流速均有显著影响。在7.5 V1、80 Hz的正弦电压驱动下,该压电微泵的最大输出流速为2.05μL/min。该文制作的微泵具有流量稳定,驱动电压较低,性能稳定可靠和易控制等优点,可满足微流体系统的使用要求。     

压电微泵驱动信号及流量影响因素分析

压电微泵的泵出流量由微泵结构、压电振子特性及驱动系统驱动信号的形式决定。在机械结构及材料特性确定的条件下,压电振子的驱动信号决定着微泵输出微流量的可靠性和稳定性。在分析压电微泵驱动基理的基础上,通过Ansys对驱动压电振子有效振动的一、二阶频率进行有限元模拟分析,确定了驱动信号电压幅值、频率对微泵流量的影响。以此为基础搭建压电微泵流量测试实验平台,在相同电压和频率条件下,研究了3种不同脉冲信号（正弦波、三角波、矩形波）对输出流量的影响。通过实验对理论模型进行修正,得到了压电微泵输出流量简化模型。实验验证了所得模型在正弦波、三角波、矩形波3种不同波形驱动下最大误差不超过4%,控制范围内可靠性在99.0%以上。综合比较可知,方波脉冲信号为压电微泵最佳驱动信号。     

镍钛合金形状记忆薄膜的化学刻蚀

镍钛合金形状记忆薄膜的图形化技术曾是其实用化的主要障碍之一,现在,一种工作性能优越的化学刻蚀液可以实现薄膜的高精度图形化,该刻蚀液常温工作,性能稳定,刻蚀速率在１～５ 微米／分之间均可得到满意的刻蚀线条。常规制作的光刻胶掩模在该刻蚀液中非常稳定。该刻蚀液用于溅射态的形状记忆合金薄膜可得到与掩模图形完全一致的刻蚀结果,刻蚀线条光滑平直,刻蚀系数大于 １５。当用于热处理以后的薄膜时,刻蚀面有一定程度的粗糙化,只能用于刻蚀相对较粗的线条,这是热处理后薄膜中晶粒与晶界刻蚀速率不同所致。用该刻蚀液图形化的形状记忆合金薄膜驱动机构已成功用于微泵制造,所制作的微泵流量达到 ２００ 微升／分钟以上。     

压电双晶片驱动的压电微泵的研究

介绍了一种基于MEMS技术的压电微泵。该微泵利用聚二甲基硅氧烷(PDMS)作为泵膜,利用双面湿法腐蚀形成被动阀,并利用压电双晶片作为驱动部件。对压电双晶片的理论变形量和压电微泵的泵腔变化量、泵腔压缩比进行了理论分析,并对其输出流量进行了测试。在100 V、20 Hz的方波驱动下,该压电微泵的最大输出流量为317μL/min。结果显示该压电微泵的制作工艺简单,具有良好的流体驱动性能。     

基于能量法的微驱动器静电弹性耦合分析

以微泵静电驱动结构为例,基于静电和弹性薄板理论,应用瑞利-黎兹能量法建立了周边固支边界条件下,静电驱动圆膜弯曲振动的谐振频率及相应振型的理论模型。位移振形的模态分析及频率计算结果均表明该计算实例的谐振频率为635Hz,为微驱动器的设计及控制提供了理论依据。     

Si/TiNi双层结构SMA电热驱动器的仿真和制造

使用射频磁控溅射法,在Si片上沉积了TiNi形状记忆合金薄膜,分别采用能谱色散光谱仪(EDS)和差示扫描热量分析(DSC)方法测试了薄膜的成分和相变特征温度,并通过给形状记忆合金(SMA)薄膜加热及冷却,观察薄膜的形变恢复情况,定性测试了SMA的形状记忆特性。在此基础上,设计并制造了一种SMA薄膜/Si膜复合膜悬臂梁结构的微驱动器。在室温下,SMA电热驱动器的悬臂梁是平直的;由于TiNi合金具有相变和形状记忆特性,当TiNi电极加上电压后,悬臂梁会产生弯曲。测试结果表明,在2.0V电压下,驱动器悬臂梁端部的驱动位移可达到70.5μm,功耗为20mW。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.