Applications of SOI-based optical MEMS

After microelectromechanical systems (MEMS) devices have been well established, components of higher complexity are now developed. Particularly, the combination with optical components has been very successful and have led to optical MEMS. The technology of choice for us is the silicon-on-insulator (SOI) technology, which has also been successfully used by other groups. The applications presented here give an overview over what is possible with this technology. In particular, we demonstrate four completely different devices: (a) a 2 × 2 optical cross connector (OXC)with an insertion loss of about 0.4 dB at a switching time of 500 μs and its extension to a 4 × 4 OXC, (b) a variable optical attenuators (VOA), which has an attenuation range of more than 50 dB (c) a Fourier transform spectrometer (FTS) with a spectral resolution of 6 nm in the visible, and (d) an accelerometer with optical readout that achieves a linear dynamic range of 40 dB over ±6 g. Except for the FTS, all the applications utilized optical fibers, which are held and self-aligned within the MEMS component by U-grooves and small leaf springs. All devices show high reliability and a very low power consumption     

RF MEMS on the radar

This article gives an overview of applications of radio frequency (RF) microelectromechanical system (MEMS) technology in radio detection and ranging (radar). RF MEMS components for radar include attenuators, limiters, (true-time-delay) phase shifters, transmit/receive (T/R) switches and tunable matching networks. Radar subsystems that benefit from RF MEMS technology include active electronically scanned arrays (T/R modules), passive electronically scanned arrays (lenses, reflect arrays, subarrays, and switched beamformers), and radomes. Using a bottom-up approach, the figures of merit for RF MEMS technology are related to the figures of merit for radar subsystems. The article also discusses ultrawideband RF MEMS reflect array and T/R module design as examples. First, electronically scanned array, radar and RF MEMS fundamentals are briefly introduced.     

MEMS optical scanners for microscopes

Microelectromechanical systems (MEMS) optical scanners have been around for more than two decades. Various applications have been presented, but few of them have advanced to the commercial level to date due to the difficulties of combination of optics and MEMS devices. This paper presents our activities of investigating MEMS scanner applications related to microscopic imaging. First, we started with developing a millimeter-sized one-dimensional scanner for commercially available laser scanning microscope. This microscope with the MEMS scanner is now commercially available. In order to take advantage of the miniaturization capability of MEMS, the next step was to miniaturize the whole optics together with the scanners. Miniaturized confocal microscope with a two-dimensional (2-D) scanner has been developed, and its feasibility and key issues are clarified. Additionally, an alternative 2-D scanner capable of scanning wide angle has been prototyped and fundamental characterization showed a promising result. Throughout the study, feasibility of MEMS optical scanners for microscopes has been demonstrated.     

A Compact and Low-Cost MEMS Loudspeaker for Digital Hearing Aids

A microelectromechanical-systems (MEMS)-based electromagnetically actuated loudspeaker to reduce form factor, cost, and power consumption, and increase energy efficiency in hearing-aid applications is presented. The MEMS loudspeaker has multilayer copper coils, an NiFe soft magnet on a thin polyimide diaphragm, and an NdFeB permanent magnet on the perimeter. The coil impedance is measured at 1.5 Omega, and the resonant frequency of the diaphragm is located far from the audio frequency range. The device is driven by a power-scalable, 0.25-mum complementary metal-oxide semiconductor class-D SigmaDelta amplifier stage. The class-D amplifier is formed by a differential H-bridge driven by a single bit, pulse-density-modulated SigmaDelta bitstream at a 1.2-MHz clock rate. The fabricated MEMS loudspeaker generates more than 0.8-mum displacement, equivalent to 106-dB sound pressure level (SPL), with 0.13-mW power consumption. Driven by the SigmaDelta class-D amplifier, the MEMS loudspeaker achieves measured 65-dB total harmonic distortion (THD) with a measurement uncertainty of less than 10%. Energy-efficient and cost-effective advanced hearing aids would benefit from further miniaturization via MEMS technology. The results from this study appear very promising for developing a compact, mass-producible, low-power loudspeaker with sufficient sound generation for hearing-aid applications.     

基于改进的 Sage-Husa 滤波 MEMS陀螺阵列降噪技术研究

为充分挖掘 MEMS 陀螺的性能,提高 MEMS 陀螺在实际应用中的精度,通过搭建四陀螺阵列结合改进的 Sage-Husa 滤 波算法对陀螺阵列的输出信号进行降噪,在不改变陀螺加工工艺和显著提高生产成本的条件下有效提高了 MEMS 陀螺仪的实 际性能。 通过分析 MEMS 陀螺仪的系统误差和随机误差,搭建误差模型,利用传统卡尔曼滤波、移动平均滤波、小波阈值去噪 和改进的 Sage-Husa 滤波算法对单个陀螺和陀螺仪阵列进行降噪处理,实验对比发现改进的 Sage-Husa 滤波算法和陀螺仪阵列 结合后能有效降低陀螺的输出噪声。 利用 Allan 方差分析陀螺仪阵列经过改进的 Sage-Husa 算法滤波后的随机误差,四陀螺阵 列角度随机游走从 0. 40°/ h降低到 0. 03°/ h ,零偏不稳定性从 71. 11°/ h 降低到 5. 83°/ h,有效提高了 MEMS 陀螺在实际应用 中的性能。     

磁性微电子机械系统(MMEMS)中的关键问题

磁性微电子机械系统(MMEMS)是在传统的微电子机械系统(MEMS)基础上发展的,它在科学研究及应用领域中有着巨大的潜力.磁性材料和MEMS技术的兼容性问题此前已作为一个重要的问题论述过.本文就磁性MEMS技术中的线圈制作、软磁膜制备及硬磁膜制备等关键性问题加以概述.     

MODELING AND SIMULATION OF PIEZOELECTRIC MEMS ENERGY HARVESTING DEVICE

ABSTRACT

Piezoelectric MEMS power generator is used to harvest energy from the ambient vibrations in the environment. This paper proposes a structure design of MEMS power generator for low-frequency applications, which is based on bulk MEMS technology and (110) Si wafer. The structure consists of a silicon cantilever with a piezoelectric layer attached. The cantilever is modeled as an Euler-Bernoulli beam with a lumped mass beneath the tip of the cantilever, and then analytical modeling and simulations are carried out using MATLAB. Simulation results show that a tradeoff between the geometric parameters and the proof mass should be made for a high output power of the device. To increase the output power, the length of piezoelectric layer can be optimized, which is not necessarily equal to that of cantilever. Simulation results point out ways to perform the optimization of MEMS power generator. The analytical modeling and simulations are also helpful for the design of macro-scale power generator.     

磁性微电子机械系统(MMEMS)的应用

微电子机械系统(MEMS)技术结合磁性材料的特性,会产生许多新的功能,并在很多领域得到应用,如信息技术、汽车工业、生物医学,航空以及科学仪器等.本文阐述了在微米尺寸下,磁性MEMS相对于静电和压电执行器,在强度、偏振、执行距离等方面具有的优势,并就磁性MEMS现有及潜在的应用加以概述.     

基于MEMS技术的汽车传感器研究进展

随着汽车传感器的迅速发展和对MEMS(微机电系统)技术研究的深入,基于MEMS技术的汽车传感器具有广阔的应用前景。本文就MEMS汽车传感器的研究应用现状、MEMS汽车传感器的分类、制作加工技术和工艺等进行了简述,并详细介绍了几种典型的MEMS汽车传感器,最后对MEMS汽车传感器今后的发展进行了探讨。     

Piezoelectric Microactuator Devices

MEMS (Microelectromechanical Systems) R&D originated from the successes of microactuator device fabrication by Si semiconductor micromachining technology. Although this technology is suitable for fabricating microstructures, the sensing and actuation capability employed is limited only to electrostatic and capacitive devices, which results in the limited functions of the devices. In particular, high force output with low power dissipation cannot be achieved by electrostatic actuation. The integration of piezoelectric materials for MEMS is thus highly encouraged to realize high force output as well as sensing capability using both piezoelectric and inverse piezoelectric effects. This integration then results in simplification of the microstructures. Promising applications of piezoactuators and the difficulties of integrating exotic piezoelectric materials in conventional micromachining processes are discussed in this paper.     

电弧故障探测与保护相关标准对比分析

电弧故障检测技术是电气防火领域一项突破性新技术。针对电弧故障探测与保护,介绍了国内外标准的应用情况,阐述了消防行业和低压电器行业国标的区别和融合特征,提出了加快使用电弧故障保护装置的建议。     

浅析MEMS传感器在智能家居领域的应用

随着物联网技术的发展,智能家电已进入千家万户,从大到一台冰箱,小到一个开关的智能设备构成了智能家居体系.物联网使智能家电能通过互联网连接进行信息交换,智能家电感知外部世界获取信息则是通过传感器实现的.当前智能家居领域的应用场景不断细化,对传感器的尺寸、功耗、价格有了更高的需求.以下介绍MEMS传感器的技术及应用、MEM...     

The Effect of Microstructure on AlN MEMS Resonator Response

Piezoelectric AlN micro- and nanoelectromechanical systems (MEMS, NEMS) resonator devices are being developed for RF filter applications. Composite structures which include the piezoelectric actuating film, metal electrode layers, and a flexural layer are required for these devices. The crystalline quality of the AlN film is strongly dependant on the growth technique used, and may significantly impact the piezoelectric response. We have fabricated MEMS resonator devices using sputtered and pulsed laser deposited (PLD) AlN thin films. Highly oriented ?0001? PLD AlN films have been deposited on platinum-terminated composite MEMS structures. Devices made using PLD films have been observed to result in significantly greater displacement, lower actuation voltage, and higher device Q than equivalent devices made with sputtered AlN films that are less crystalline and may have different stoichiometry. AlN thin film deposition, device fabrication, and modeshape analysis of resultant MEMS resonator devices are discussed for sputtered and PLD AlN films.     

汽车电气系统MEMS传感器可靠性设计研究

随着汽车传感器的迅速发展和MEMS(微机电系统)技术的深入研究,基于MEMS技术的汽车传感器具有广阔的应用前景.分析了汽车电气系统中MEMS传感器的可靠性设计研究应用现状及问题,提出了基于阶段主导可靠性因素的MEMS汽车传感器可靠性设计方法;对汽车应用环境下的失效模式、失效机理进行了讨论;并对如何对MEMS传感器系统寿命分布模型进行定量描述做了初步探讨.最后对MEMS汽车传感器可靠性今后的发展研究进行了探讨.     

RF MEMS phase shifters: design and applications

Recent results obtained with MEMS phase shifters demonstrate that their performance is much better than GaAs phase shifters using either standard (switched-line, reflect-line) or distributed designs. The reliability of MEMS phase shifters is worse than of single switches since they employ 8-16 MEMS switches and do not tolerate a failure in any of the switches. On the other hand, a large phased array will still function properly, albeit with a slightly decreased efficiency and higher sidelobes if 3-4% of the phase shifters fail. Currently, the failure mechanisms of MEMS switches are being investigated and will greatly benefit the reliability of MEMS phase shifters. Also, the hermetic packaging of MEMS phase shifters is not straightforward, due to their relatively large size. It is for these reasons that the authors believe that MEMS phase shifters will be mostly used in satellite and defense applications in the next five years     

Electroceramics Research in India

Electroceramics research is driven by the technology development needs and the device applications in the fields of microelectronics, communications, automation, energy conservation, MEMS and others. Ferroelectric ceramics have been technically exploited because of their unique properties such as high dielectric permittivity, high piezoelectric & electromechanical coupling and discovery of electrical poling process. Under certain circumstances they show high optical transparency and electro-optic coefficients. High permittivity barium titanate based piezoelectric ceramics and their polymer composites show unusual properties for a wide range of applications in sonars, ultrasonic cleaners, micro-accelerometers, hydrophones, surface acoustic wave filters, delay lines, and microactuators etc. A number of organizations in India viz. academic institutions, research laboratories and industries are involved in the preparation, characterization and device fabrication of the electroceramic materials. This paper presents an overview of the ongoing work and the future prospects.     

Opportunities and challenges for MEMS in lightwave communications

Over the remarkably short interval of just a few years, optical microelectromechanical systems (MEMS) have breached the gulf from laboratory curiosity to advanced development and early trial deployment in lightwave-communications systems. This owes largely to the ease with which the technology has demonstrated high optical quality and reasonably fast tuning and switching subsystems that are compact and potentially low in cost. Lightwave micromachines now threaten to make possible functional structures for building tunable lasers and filters, dynamic gain-equalizers, chromatic dispersion-compensators, wavelength-add-drop multiplexers, and polarization-controllers that represent substantial improvements over the conventional state of the art. More extravagant yet, both in promise and in expectations, is the potential of MEMS as a means of building the large-port-count optical switches that are just now becoming needed by emerging mesh-based core transport networks. In this paper, we review the current status and prospects for MEMS in lightwave communications, with particular emphasis on high-port-count core optical cross connects, and discuss challenges that still confront this technology     

微能源

微电子机械系统 (MEMS———MicroElectroMechanicalSystems) ,是指运用微电子加工技术和微机械加工技术 ,在较小的物理尺寸上 ,集成了微机械元件 ,微传感器 ,微机械执行器 ,微电子元件、电路和供能部件的器件或是系统。目前供能问题已经成为MEMS降低成本、进入实用化、自动化的最大障碍。现有的一个解决方案是微能源。介绍了微能源技术的发展和技术现状 ,分别讨论了微型内燃机系统、微燃料电池、微太阳电池、微型锂电池、微型核电池等几种微能源的制造工艺 ,工作特性以及应用现状。简单分析了微能源的发展方向和应用前景。     

基于DSP测量组合导航系统设计

随着微机电系统(MEMS)技术的发展,采用MEMS技术的微小型低成本捷联惯性导航系统已成为目前的一个研究热点;而单一的导航定位定向系统已经不能满足我国在军事领域和民用领域对导航、定位、定向精度的要求,以捷联惯导系统(SINS)和全球定位系统(GPS)相结合构成的组合导航系统以其较高的精度、低廉的成本逐渐被应用于各个领域.本文以MEMS芯片为基础,研究基于DSP测量的低成本SINS/GPS组合导航系统的设计和实现,旨在实现组合导航系统小型化、低成本、高可靠性和智能化.     

室内微型组合导航计算机设计

通过对室内导航技术的分析,结合嵌入式控制技术和和微机电系统(micro electro mechanical systems,MEMS)技术,提出了基于MEMS惯性/视觉的室内微型组合导航计算机设计方案。该方案以室内导航的性能需求为基础,设计了以MEMS惯性传感器和摄像头为主要传感器电路,并融合各模块数据完成了计算机系统设计。测试结果表明该系统能够正确采集前方障碍物的距离信息和运动信息,体积小,可靠性高,满足室内导航的要求。