Benchtop Polymer MEMS

Loctite photopatternable adhesives 3108, 3340, and 3525 are introduced for microelectromechanical systems (MEMS) applications. These materials are patterned within minutes by exposure to ultraviolet (UV) light followed by rinsing with a solvent; no further processing is required. Because the uncured fluid is relatively insensitive to room light, this can be done on any lab bench without the requirement for a clean room. The materials can be spin-coated to obtain films, or cast between spacers for layers up to 1 cm thick, and the cured polymers range from elastomeric to rigid. These adhesives are of interest for rapid, inexpensive fabrication of relatively low-resolution features (tens to hundreds of micrometers) by photocuring. They can alternatively be molded, like polydimethylsiloxane (PDMS), to achieve high resolution, as well as irreversibly bonded after an O$_2$plasma treatment. In addition, like SU8, they can be used as molds for patterning PDMS. Initial characterization of resolution, swelling, and biocompatibility were performed. One of the polymers, 3340, can be used for packaging bioMEMS-on-complementary-metal–oxide-semiconductor (CMOS) chips, exploiting its biocompatibility and its photopatternability at thicknesses of 1500$mu$m to cover the bond wires while exposing the chip surface. As further demonstrations of the versatility of these materials, multilevel, interconnected channel structures were fabricated with a gelatin sacrificial layer, and magnetic films were prepared, since the polymers remain patternable even with additives.1535     

微谐振器结构性能的有限元分析

微谐振器是试飞测试系统的重要组成部件,微谐振器的性能影响到试飞测试系统的精确度.为了提高微谐振器的性能,在传统结构的基础上,提出改变微谐振器中折叠梁、驱动梳齿等结构的尺寸来改善其性能.运用有限元法对不同结构尺寸下的微谐振器进行模态、品质因子分析.仿真结果表明,横向微谐振器的一阶模态频率的大小很大程度上受到折叠梁尺寸的影响;静电梳齿的尺寸设计中,梳齿的宽度是影响驱动力和品质的一个关键因素.仿真结果表明,对提高微谐振器的性能具有一定的指导意义.     

炭黑填充聚乙烯导电复合材料气敏性能研究

采用溶液共混法成功制备出炭黑/聚乙烯导电气敏复合材料,研究了在苯、甲苯、二甲苯三种有机溶剂蒸汽中的电阻变化.实验结果表明,该复合材料在二甲苯蒸汽中电阻变化最大,在苯蒸汽中电阻变化最小.进一步研究了其在100 ppm至800 ppm(ppm=10-6)二甲苯蒸汽中的气敏响应性,实验结果表明:复合材料的灵敏度从0.04增大至0.11.     

静电梳微振子结构和特性研究

较系统地研究了静电梳驱动微振子的结构和工作原理，导出了微振子的谐振频率、品质因子及跨导等参数，以及相应的力学和电学模型，并研究了空气粘滞效应对品质因子的影响，在此基础上，设计出几种不同尺寸，不同形状的微型谐振子结构，并用表面微机械加工方法成功地制成了能横向振动的静电梳微振子，实测得到的谐振频率在７．５￣９．０ｋＨｚ范围内，在空气中品质因子为１００左右，与理论计算能较好符合。     

导电聚合物电极同时测定痕量铜、铅、镉、锌

使用一种新型导电聚合物电极作为工作电极,采用阳极溶出伏安法通过同位镀铋对导电聚合物电极进行修饰,实现了痕量铜、铅、镉、锌的同时测定.比较了导电聚合物电极和丝网印刷碳电极的性能,研究了预富集时间和不同介质对重金属离子测定的影响规律.结果表明:铜、铅、镉、锌在铋膜修饰的导电聚合物电极上分别在0.05 V、-0.55 V、-0.80 V、-1.10 V产生灵敏的电位溶出峰,峰高与离子浓度线性相关,最低检测限分别可达到0.5 μg/L、1 μg/L、1 μg/L和0.5 μg/L.在检测重金属离子方面,导电聚合物电极比丝网印刷碳电极更加灵敏和稳定,为一次性电化学传感器的发展提供了良好的基础.     

Blended Hermite interpolants

In (Röschel, l997) B-spline technique was used for blending of Lagrange interpolants. In this paper we generalize this idea replacing Lagrange by Hermite interpolants. The generated subspline b(t) interpolates the Hermite input data consisting of parameter values t_i and corresponding derivatives a_i,j, j=0,…,_i−1, and is called blended Hermite interpolant (BHI). It has local control, is connected in affinely invariant way with the input and consists of integral (polynomial) segments of degree 2·k−1, where k−1max{_i}−1 denotes the degree of the B-spline basis functions used for the blending. This method automatically generates one of the possible interpolating subsplines of class C^k−1 with the advantage that no additional input data is necessary.     

Blended deformable models

This paper develops a new class of parameterized models based on the linear interpolation of two parameterized shapes along their main axes, using a blending function. This blending function specifies the relative contribution of each component shape on the resulting blended shape. The resulting blended shape can have aspects of each of the component shapes. Using a small number of additional parameters, blending extends the coverage of shape primitives while also providing abstraction of shape. In particular, it offers the ability to construct shapes whose genus can change. Blended models are incorporated into a physics-based shape estimation framework which uses dynamic deformable models. Finally, we present experiments involving the extraction of complex shapes from range data including examples of dynamic genus change     

微机电系统的封装技术

MEMS封装是在微电子封装技术基础上发展起来的一项关键的MEMS技术。介绍了MEMS封装技术的功能、特点与分类。在此基础上,重点介绍了键合技术、上下球栅阵列技术、倒装芯片技术、多芯片技术以及3-D技术等几种重要的MEMS封装技术。最后,进一步探讨了MEMS封装的发展趋势及研究方向。     

High-performance MEMS shutter display with metal-oxide thin-film transistors and optimized MEMS element

Active matrix prestressed microelectromechanical shutter displays enable outstanding optical properties as well as robust operating performance. The microelectromechanical systems (MEMS) shutter elements have been optimized for higher light outcoupling efficiency with lower operation voltage and higher pixel density. The MEMS elements have been co-fabricated with self-aligned metal-oxide thin-film transistors (TFTs). Several optimizations were required to integrate MEMS process without hampering the performance of both elements. The optimized display process requires only seven photolithographic masks with ensuring proper compatibility between MEMS shutter and metal-oxide TFT process.     

MEMS传感器——无人机的核心

无人机的市场规模和范围持续蓬勃发展,新应用程序不断涌现,而高品质MEMS传感器和先进软件对其发展至关重要。本文详细介绍了无人机的几种关键性传感器以及对无人机性能的影响,如惯性测量单元、气压传感器、地磁传感器、应用特定型传感器节点和传感器数据融合,并介绍了Bosch Sensortec的相关产品在无人机上的应用。     

MEMS封装技术

介绍了微机电(MEMS)封装技术,包括晶片级封装、单芯片封装和多芯片封装、模块式封装与倒装焊3种很有前景的封装技术。指出了MEMS封装的几个可靠性问题,最后,对MEMS封装的发展趋势作了分析。     

MEMS Switched Tunable Inductors

This paper presents a new implementation of integrated tunable inductors using mutual inductances activated by micromechanical switches. To achieve a large tuning range and a high quality factor, silver was used as the structural material, and silicon was selectively removed from the backside of the substrate. Using this method, a maximum tuning of 47% at 6 GHz is achieved for a 1.1 nH silver inductor fabricated on a low-loss polymer membrane. The effect of the quality factor on the tuning characteristic of the inductor is investigated by comparing the measured result of identical inductors fabricated on various substrates. To maintain the quality factor of the silver inductor, the device was encapsulated using a low-cost wafer-level polymer packaging technique.     

MEMS集成滤波器技术

滤波器是频率转换系统(如,调谐电路、接收器)的基本构成模块。借助于MEMS技术实现的滤波器不仅带来插入损耗、功耗、线性等性能的改善,也有利于将整个通信前端集成到单一芯片上。综述了MEMS可调滤波器的研究进展。与单一利用MEMS电容的调变实现频率可调的滤波器相比,分形可调MEMS滤波技术有更小的插入损耗和更宽的调频范围。     

Lateral MEMS microcontact considerations

A lateral switching relay structure has been developed which provides a double gold contact with as low as 70-mΩ measured contact resistance, 0.45-A current-carrying ability at MEMS compatible force levels, TTL compatible actuation, and air gap isolation when open. The die area used for the relay mechanism itself (distinct from the actuation) is approximately 75 μm by 100 μm and was designed to allow fabrication of the relays in the MCNC MUMP's dual polysilicon foundry process with no assembly. Design analysis shows that substantial characterization is needed to design optimal microrelays. Temperature softening and failure modes have been characterized by current voltage techniques. Polysilicon vernier structures were used to develop force/current/conductance curves. Relays using thermal actuators have been built     

Blended call center performance analysis

The performance analysis of blended PSTN and IP call centers is likely to be in demand in the near future as the technology for these centers develops further. The authors did not find an analysis for a system of this type in the literature. The development of a user-friendly and portable tool based on their analysis methodology should be useful to organizations that have implemented, or are considering implementing, a blended call center. We have shown BCAT's wide range of uses. In the future, we plan to enhance BCAT to allow for skills-based routing to, for example, agents who can handle PSTN calls only, IP calls only, or both call types. This is a much more complicated queueing problem to model, but will provide increased flexibility to call center supervisors in terms of workforce management planning     

MEMS的协同仿真

仿真是微机电系统(MEMS) 设计的重要手段.目前MEMS中的集成仿真方法对设计人员要求太高从而限制了其使用范围.为了充分发挥仿真在MEMS设计中的作用,把协同设计的思想引入MEMS仿真中,提出了协同仿真的设计方式.构建了MEMES的协同仿真框架,分析了其仿真流程和数据文件的构成,并阐述了节点载荷映射的混合法.最后对一个MEMS器件进行协同仿真并与集成仿真的结果进行了比较,证明了方法的可行性.     

Planarity of large MEMS

A systematic approach is developed to study the planarity of large (few mm long) micromechanical cantilever beams made of μm-size features. The beams are made by the SCREAM (single crystal reactive etching and metallization) process. SCREAM beams consist of a single crystal silicon (SCS) core coated on top and sides by oxide or nitride and a metal. The sidewalls overhang the SCS core. The beams deform out of plane due to thermal and intrinsic strains of the coating films. These strains are defined and measured for plasma deposited SiO₂ and sputtered aluminum films. A linear elastic model of SCREAM cantilever beams is then developed to evaluate the deformation of the beams caused by film strains. The model predicts that the beams may bend up or down or remain planar depending on their cross-sectional design. Also, the greater the depth of the beams, the more planar they are, and a change in temperature (room temp-100°C) has little influence on planarity for beams with thin (~.2 μm) metallization. The model is validated by fabricating large (up to 2 mm long) cantilever beams, 1 and 2 μm wide, with PECVD SiO₂ and sputtered Al coatings. The deformations of the beams prior to metallization as well as before and after annealing of the metallized beams are measured. Good agreement is obtained between the experimental deformations and those predicted by the model. The paper is concluded with an example of a working, large (4×5 mm²), planar MEM device fabricated by the SCREAM process