A Large-Area High-Reflectivity Broadband Monolithic Single-Crystal-Silicon Photonic Crystal Mirror MEMS Scanner With Low Dependence on Incident Angle and Polarization

In this paper, we introduce a single-axis resonant combdrive microelectromechanical systems (MEMS) scanner with a large-area highly reflective broadband monolithic single-crystal-silicon (SCS) photonic crystal (PC) mirror. PC mirrors can be made from a single monolithic piece of silicon through alternate steps of etching and oxidation. This process allows the fabrication of a stress-free PC reflector in SCS with better optical flatness than deposited films such as polysilicon slabs on low-index oxide. PC mirrors can be made in IR transparent dielectric material and can achieve high reflectivity over a broad wavelength range. PC reflectors have several advantages over other mirror technologies. They can tolerate much higher processing temperatures and higher incident optical powers as well as operate in more corrosive environments than metals. Compared to multilayer dielectric stacks, PC mirrors allow for simpler process integration, thus making them highly compatible with CMOS and MEMS processing. In this paper, we fabricate a PC mirror MEMS scanner in SCS without any deposited films. Our PC mirrors show broadband high reflectivity in the wavelength range from 1550 to 1600 nm, and very low angular and polarization dependence over this same range. The single-axis MEMS scanners are fabricated on silicon-on-insulator (SOI) wafers with the PC mirrors also fabricated in the SOI device layer. The scanners are actuated by electrostatic comb drives on resonance. Dynamic deflection measurements show that the scanners achieve 22deg total scan angle with an input square wave of 67 V and have a resonance frequency of 2.13 kHz.     

硅基微型静电谐振式直流电场传感器建模与仿真分析

微机电系统(micro-electro-mechanical system,MEMS)电场传感器因其体积小、功耗低、成本低、易于量产等优势在电力系统具有广泛应用前景。以静电式电极共面水平谐振MEMS直流电场传感器为研究对象,针对其驱动单元、运动过程和感应单元,分别建立基于静电力驱动的传感器动力学模型和基于静电感应的敏感结构电学模型,实现了微型电场传感器的多物理场模型集成。所建立的模型可定量表征传感器的输出特性以及相关结构尺寸对传感器性能的影响。通过仿真计算发现,适当减少齿宽与齿间距、增加感应齿长,可以提高该类型传感器的输出电流,进而提高其测量灵敏度。该文的研究成果可为微型电场传感器的设计和性能优化提供参考。     

Are Diamonds a MEMS' Best Friend?

Next-generation military and civilian communication systems will require technologies capable of handling data/ audio, and video simultaneously while supporting multiple RF systems operating in several different frequency bands from the MHz to the GHz range [1]. RF microelectromechani-cal/nanoelectromechanical (MEMS/NEMS) devices, such as resonators and switches, are attractive to industry as they offer a means by which performance can be greatly improved for wireless applications while at the same time potentially reducing overall size and weight as well as manufacturing costs.     

Tools for real-time business integration and collaboration

Business integration platforms (a.k.a. middleware), enable companies to improve integration of information systems, integration with partners, automation of business processes and workflow, and real-time visibility into the operations. Middleware is an important component in building a flexible, scalable, fault tolerant, secure, standards-based, IT architecture. It reduces application development and maintenance costs, and it allows best-of-breed application deployment where systems can be expanded incrementally by plugging in new applications into a message bus. As such, it positions utilities to manage business structure and business process changes introduced by wholesale and retail deregulation. More than 100 utilities and two ISOs have already acquired middleware, and many have successfully applied it. Applications include back-office applications integration, trade floor applications integration, integration with energy exchanges, eProcurement, retail applications integration, and T&D midoffice integration. Reported experiences have been very positive. Applications of middleware to real-time control and distributed resources integration are yet to come.     

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.     

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.     

Filter technologies for wireless base stations

Phenomenal growth in the telecommunication industry in recent years has brought significant advances in filter technology as new communication systems emerged, demanding more stringent filter characteristics. In particular, the growth of the wireless communication industry has spurred tremendous activity in the area of microwave filter miniaturization and has been responsible for many advances made in this field. The filters that are currently being used in wireless base stations can be divided into two main categories: coaxial cavity resonator filters and dielectric resonator (DR) filters. While coaxial cavity filters have limited quality factor (Q) values, they offer the lowest cost design and are still being widely employed, particularly in wide bandwidth applications. With increased demands for high performance wireless systems, dielectric resonator filters are emerging as the baseline design for wireless base stations. Over the next five years, dielectric resonator filters are expected to have a significant share of the overall wireless base station filter market. High-temperature superconductor (HTS) filters are also expected to have a share of this market, particularly for systems, which have very stringent requirements for out-of-band interference. In this article, we begin by reviewing the main filter requirements, highlighting the technologies that are being currently employed. Emerging filter technologies that have the potential to replace the existing technologies are then described.     

The application of thick-film technology in C-MEMS

Laminated 3D structures made using low-temperature co-fired ceramic (LTCC) technology are practical for ceramic micro-electro-mechanical systems (C-MEMS). The sensors for mechanical quantities, and/or actuators, are fundamental parts of MEMS. Thick-film resistors can be used to sense the mechanical deformations, and thick-film piezoelectric materials can be used as electro-mechanical transducers in a C-MEMS structure. The integration of these thick-film materials on LTCC substrates is in some cases difficult to realise due to interactions with the rather glassy LTCC substrates. The subject of our work is an investigation of thick-film materials for electro-mechanical transducers (sensors and actuators) and their compatibility with LTCC substrates. Resistors made with commercial thick-film resistor materials for use as sensors on LTCC substrates have been investigated and evaluated. Ferroelectric ceramic materials based on solid solutions of lead zirconate titanate (PZT) with low firing temperatures around 850°C were developed for thick-film technology and evaluated on LTCC substrates.     

微电机系统(MEMS)的测试问题

微电机系统（MEMS）是在IC工艺技术基础上发展起来的一项重大科学技术,有着广阔的应用前景,但是它的测试问题从设计开始到批量生产,都面临着巨大的挑战。本文简单地论述了它们面临当的测试问题。     

Curriculum development in microelectromechanical systems inmechanical engineering

Curriculum development in microelectromechanical systems (MEMS) in the Mechanical Engineering and Applied Mechanics (MEAM) Department at the University of Michigan is presented. A course curriculum structure that integrates both mechanical and electrical engineering courses is proposed for mechanical engineering students. The proposed curriculum starts from undergraduate study and finishes at the Ph.D. level. Two new graduate-level MEMS courses are proposed: “Introduction to MEMS” for senior undergraduate students and entry-level graduate students and “Advanced MEMS” for graduate students. The first course has been experimentally taught at the University of Michigan for three years and the class assessments are summarized and analyzed in this paper. It is clear from the student responses that they are interested in taking courses in emerging technologies such as MEMS and more courses in the MEMS area should be offered. Future MEMS curriculum development and a new MEMS course for undergraduate-level students in the college of engineering are discussed     

智能照明系统综述及浅析

在照明行业日渐以智能化为主打标签的形势下,智能照明技术领域发展迅猛,作为一个新兴起的产品类别,存在许多未知的市场空间和巨大发展潜力。各大企业争先涌入开创市场,技术形式百家争鸣,但许多技术还没有系统的标准解释,行业也欠缺权威的认证模式,导致市场还尚未成熟。本文主要梳理了智能照明发展现状、目前智能照明系统框架和功能,浅评智能照明系统尚存的不足并探讨未来智能照明系统模型发展方向。     

基于FPSLIC的射频识别发送通道设计与实现

提出一种基于FPSLIC的射频识别发送通道SoC设计方案,对比分析了FPSLIC在射频识别中的应用优势。将IS015693技术标准与FPSLIC的特点相结合,单芯片集成实现了编码与调制等功能,并设计合适的调制信号放大与匹配电路。这种方案提高了系统的集成度与可靠性,加长了读写器的工作距离。     

电力市场中发电公司间心照不宣的勾结浅析

电力工业所固有的特征使得电力市场更接近于寡头垄断市场.在这样的市场中,除了存在静态的市场势力问题以外,还可能存在动态的勾结问题.这些问题都会对电力市场的竞争性产生负面影响,降低其运营效率.就电力市场中的市场势力问题国内外提出一些识别方法和抑制措施,而对于电力市场中的勾结问题,研究工作则刚刚开始.由于勾结可以采取多种不同的形式,难以判别,但勾结对市场运营的危害性比滥用市场势力更为严重,因而已成为一个受到广泛关注的重要而难以解决的问题.文中主要针对电力市场中的勾结现象进行分析,解释了产生勾结的原因,分析了影响勾结形成与维持的因素,如竞争者数量、市场进入壁垒、市场结算模式、需求侧因素的影响等,同时讨论了识别勾结现象的方法.最后对防止勾结现象的产生给出了一些建议.     

Optical MEMS for photonic switching-compact and stable optical crossconnect switches for simple, fast, and flexible wavelength applications in recent photonic networks

We review the development trends and state-of-the-art technologies of large-port-count optical switches over the past decade. Practical implementation of optical switch fabrics is discussed in terms of optical switch architectures, optical configurations, port counts, switch elements, and so on. We describe compact and stable optical crossconnect three-dimensional microelectromechanical systems (3-D-MEMS) switches that are a key technology in recent photonic networks. To show how these enable simple, fast, and flexible wavelength applications in the photonic layer, we discuss the fast and stable MEMS switching by novel comb actuator and V-shaped torsion bar, compact optical configuration with roof-type mirror, stable switch housing with cubic structure, packaging techniques by tolerance expansion and simple procedures of the component assembly, MEMS mirror controller with fast and low power digital notch circuit, reliability by shock absorption, and field trials. In addition, we discuss the impact of these switches on system integration for recent metropolitan area networks and enterprise networks.     

Influence of micromachining on dynamic behaviour of mems structures

The field of microsystems technology, comprising both micromechanical and microelectronics components, has a tremendous potential for sensing, actuation and machines at the micro level of matter in almost every field of interest to humanity, from DNA sequencing to information and communication systems. The success of microdevices depends on the effectiveness of the design synthesis in incorporating the influences of structural geometry, micromachining, microfabrication and operating environment. This paper presents and applies the concept of boundary conditioning in order to quantify the influence of micromachining on the behaviour of microstructures. An example of a device fabricated through a multi-user microelectromechanical systems (MEMS) processes (MUMPs) process is also discussed in detail.     

BioMEMS devices for drug delivery

Successful therapeutic outcomes following the administration of drugs, including small molecules and large biomolecules, require not only the selection of a proper drug but also its delivery to the proper site of action, with proper temporal presentation. Drug delivery is an extremely broad area of research, as each molecule presents its own absorption, distribution, metabolism, excretion, and toxicology (ADMET) profile. Moreover, timing of drug release may affect the efficacy of a pharmacologic agent. Any means by which drug delivery can be actuated and controlled is, therefore, of interest, and there should be no surprise that microelectromechanical systems (MEMS) have received considerable attention over the past decade in the drug delivery field. The ability to generate two-dimensional (2-D) and three-dimensional (3-D) material constructs accurately and reproducibly using MEMS may lead to substantial advances over conventional drug delivery systems.     

Analysis - MOVING ON FROM MOORE

A Belgian research centre whose pioneering use of 'open innovation' has provided vital technology for most of the world's largest semiconductor companies is changing the way it works, in a bid to meet new technological and innovation challenges. IMEC, based in Leuven, runs collaborative research and development programmes to develop next-generation manufacturing processes for key chip companies. It works by setting out a programme for developing these processes, then inviting companies to become partners in the pre-competitive work. IMECs launch a 'More than Moore' programme, under which it has combined many of its research teams into a single multi-disciplinary organisation headed by Luc Van den hove, acting as chief operating officer. This is expected to improve the way the scientific disciplines work together, which is becoming ever more important as technology solutions are increasingly driven by end applications. The programme will develop variants of IMECs mainstream 130 nm manufacturing process on 200 mm wafers, tuned to particular applications or to enable the integration of other technologies     

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     

Event correlation

The advent of modern computer technology has enabled the development of many complex man-made systems. These include discrete manufacturing systems, communication networks, computer systems, traffic control systems, and inventory systems. A common characteristic of these systems is that they have discrete states (e.g., idle, processing, queue empty/full, and normal/faulty). Also, their state transition is triggered by events (e.g., part arrival/dispatch, alarms, commands, and timeout). For this reason, these systems are called discrete event systems or event-driven systems. As today's industry moves towards more complex, distributed and heterogeneous discrete event systems, there is a growing need for integration, consolidation, correlation, and distribution of the events coming from the systems. Event correlation achieves those objectives using methods borrowed mostly from artificial intelligence and formal methods. Historically, event correlation systems were developed for real-time monitoring of many classical mission-critical systems such as power plant and water/gas/oil distribution systems. Recently, it has been spreading into new areas such as messaging, network management and computer intrusion detection     

多MEMS陀螺数据融合方法性能比较

MEMS陀螺的体积小、成本低,便于集成,但其低精度极大的限制了MEMS陀螺在实际中的应用。利用多传感器融合技术进行误差补偿可提高MEMS陀螺的测量精度,人们提出了多种数据融合方法用于改进MEMS陀螺的测量精度。对多尺度融合方法、卡尔曼滤波融合和小波阈值融合方法进行比较分析。理论分析与实验结果表明,多尺度融合算法相比卡尔曼滤波融合和小波阈值融合方法在标准差、信噪比、功率谱及Allan方差等方面性能获得了较好的效果,其适用范围更宽。