Sensors & Transducers - University Of Missouri

1y ago
2 Views
1 Downloads
1.77 MB
16 Pages
Last View : 16d ago
Last Download : 2m ago
Upload by : Philip Renner
Transcription

Sensors & TransducersVolume 115, Issue 4,April 2010www.sensorsportal.comISSN 1726-5479Editors-in-Chief: professor Sergey Y. Yurish, tel.: 34 696067716, fax: 34 93 4011989, e-mail: editor@sensorsportal.comEditors for Western EuropeMeijer, Gerard C.M., Delft University of Technology, The NetherlandsFerrari, Vittorio, Universitá di Brescia, ItalyEditor South AmericaCosta-Felix, Rodrigo, Inmetro, BrazilEditors for North AmericaDatskos, Panos G., Oak Ridge National Laboratory, USAFabien, J. Josse, Marquette University, USAKatz, Evgeny, Clarkson University, USAEditor for AsiaOhyama, Shinji, Tokyo Institute of Technology, JapanEditor for Eastern EuropeSachenko, Anatoly, Ternopil State Economic University, UkraineEditor for Asia-PacificMukhopadhyay, Subhas, Massey University, New ZealandEditorial Advisory BoardAbdul Rahim, Ruzairi, Universiti Teknologi, MalaysiaAhmad, Mohd Noor, Nothern University of Engineering, MalaysiaAnnamalai, Karthigeyan, National Institute of Advanced Industrial Scienceand Technology, JapanArcega, Francisco, University of Zaragoza, SpainArguel, Philippe, CNRS, FranceAhn, Jae-Pyoung, Korea Institute of Science and Technology, KoreaArndt, Michael, Robert Bosch GmbH, GermanyAscoli, Giorgio, George Mason University, USAAtalay, Selcuk, Inonu University, TurkeyAtghiaee, Ahmad, University of Tehran, IranAugutis, Vygantas, Kaunas University of Technology, LithuaniaAvachit, Patil Lalchand, North Maharashtra University, IndiaAyesh, Aladdin, De Montfort University, UKBahreyni, Behraad, University of Manitoba, CanadaBaliga, Shankar, B., General Monitors Transnational, USABaoxian, Ye, Zhengzhou University, ChinaBarford, Lee, Agilent Laboratories, USABarlingay, Ravindra, RF Arrays Systems, IndiaBasu, Sukumar, Jadavpur University, IndiaBeck, Stephen, University of Sheffield, UKBen Bouzid, Sihem, Institut National de Recherche Scientifique, TunisiaBenachaiba, Chellali, Universitaire de Bechar, AlgeriaBinnie, T. David, Napier University, UKBischoff, Gerlinde, Inst. Analytical Chemistry, GermanyBodas, Dhananjay, IMTEK, GermanyBorges Carval, Nuno, Universidade de Aveiro, PortugalBousbia-Salah, Mounir, University of Annaba, AlgeriaBouvet, Marcel, CNRS – UPMC, FranceBrudzewski, Kazimierz, Warsaw University of Technology, PolandCai, Chenxin, Nanjing Normal University, ChinaCai, Qingyun, Hunan University, ChinaCampanella, Luigi, University La Sapienza, ItalyCarvalho, Vitor, Minho University, PortugalCecelja, Franjo, Brunel University, London, UKCerda Belmonte, Judith, Imperial College London, UKChakrabarty, Chandan Kumar, Universiti Tenaga Nasional, MalaysiaChakravorty, Dipankar, Association for the Cultivation of Science, IndiaChanghai, Ru, Harbin Engineering University, ChinaChaudhari, Gajanan, Shri Shivaji Science College, IndiaChavali, Murthy, VIT University, Tamil Nadu, IndiaChen, Jiming, Zhejiang University, ChinaChen, Rongshun, National Tsing Hua University, TaiwanCheng, Kuo-Sheng, National Cheng Kung University, TaiwanChiang, Jeffrey (Cheng-Ta), Industrial Technol. Research Institute, TaiwanChiriac, Horia, National Institute of Research and Development, RomaniaChowdhuri, Arijit, University of Delhi, IndiaChung, Wen-Yaw, Chung Yuan Christian University, TaiwanCorres, Jesus, Universidad Publica de Navarra, SpainCortes, Camilo A., Universidad Nacional de Colombia, ColombiaCourtois, Christian, Universite de Valenciennes, FranceCusano, Andrea, University of Sannio, ItalyD'Amico, Arnaldo, Università di Tor Vergata, ItalyDe Stefano, Luca, Institute for Microelectronics and Microsystem, ItalyDeshmukh, Kiran, Shri Shivaji Mahavidyalaya, Barshi, IndiaDickert, Franz L., Vienna University, AustriaDieguez, Angel, University of Barcelona, SpainDimitropoulos, Panos, University of Thessaly, GreeceDing, Jianning, Jiangsu Polytechnic University, ChinaKim, Min Young, Kyungpook National University, Korea SouthDjordjevich, Alexandar, City University of Hong Kong, Hong KongDonato, Nicola, University of Messina, ItalyDonato, Patricio, Universidad de Mar del Plata, ArgentinaDong, Feng, Tianjin University, ChinaDrljaca, Predrag, Instersema Sensoric SA, SwitzerlandDubey, Venketesh, Bournemouth University, UKEnderle, Stefan, Univ.of Ulm and KTB Mechatronics GmbH, GermanyErdem, Gursan K. Arzum, Ege University, TurkeyErkmen, Aydan M., Middle East Technical University, TurkeyEstelle, Patrice, Insa Rennes, FranceEstrada, Horacio, University of North Carolina, USAFaiz, Adil, INSA Lyon, FranceFericean, Sorin, Balluff GmbH, GermanyFernandes, Joana M., University of Porto, PortugalFrancioso, Luca, CNR-IMM Institute for Microelectronics andMicrosystems, ItalyFrancis, Laurent, University Catholique de Louvain, BelgiumFu, Weiling, South-Western Hospital, Chongqing, ChinaGaura, Elena, Coventry University, UKGeng, Yanfeng, China University of Petroleum, ChinaGole, James, Georgia Institute of Technology, USAGong, Hao, National University of Singapore, SingaporeGonzalez de la Rosa, Juan Jose, University of Cadiz, SpainGranel, Annette, Goteborg University, SwedenGraff, Mason, The University of Texas at Arlington, USAGuan, Shan, Eastman Kodak, USAGuillet, Bruno, University of Caen, FranceGuo, Zhen, New Jersey Institute of Technology, USAGupta, Narendra Kumar, Napier University, UKHadjiloucas, Sillas, The University of Reading, UKHaider, Mohammad R., Sonoma State University, USAHashsham, Syed, Michigan State University, USAHasni, Abdelhafid, Bechar University, AlgeriaHernandez, Alvaro, University of Alcala, SpainHernandez, Wilmar, Universidad Politecnica de Madrid, SpainHomentcovschi, Dorel, SUNY Binghamton, USAHorstman, Tom, U.S. Automation Group, LLC, USAHsiai, Tzung (John), University of Southern California, USAHuang, Jeng-Sheng, Chung Yuan Christian University, TaiwanHuang, Star, National Tsing Hua University, TaiwanHuang, Wei, PSG Design Center, USAHui, David, University of New Orleans, USAJaffrezic-Renault, Nicole, Ecole Centrale de Lyon, FranceJaime Calvo-Galleg, Jaime, Universidad de Salamanca, SpainJames, Daniel, Griffith University, AustraliaJanting, Jakob, DELTA Danish Electronics, DenmarkJiang, Liudi, University of Southampton, UKJiang, Wei, University of Virginia, USAJiao, Zheng, Shanghai University, ChinaJohn, Joachim, IMEC, BelgiumKalach, Andrew, Voronezh Institute of Ministry of Interior, RussiaKang, Moonho, Sunmoon University, Korea SouthKaniusas, Eugenijus, Vienna University of Technology, AustriaKatake, Anup, Texas A&M University, USAKausel, Wilfried, University of Music, Vienna, AustriaKavasoglu, Nese, Mugla University, TurkeyKe, Cathy, Tyndall National Institute, IrelandKhan, Asif, Aligarh Muslim University, Aligarh, IndiaSapozhnikova, Ksenia, D.I.Mendeleyev Institute for Metrology, RussiaSaxena, Vibha, Bhbha Atomic Research Centre, Mumbai, India

Ko, Sang Choon, Electronics. and Telecom. Research Inst., Korea SouthKockar, Hakan, Balikesir University, TurkeyKotulska, Malgorzata, Wroclaw University of Technology, PolandKratz, Henrik, Uppsala University, SwedenKumar, Arun, University of South Florida, USAKumar, Subodh, National Physical Laboratory, IndiaKung, Chih-Hsien, Chang-Jung Christian University, TaiwanLacnjevac, Caslav, University of Belgrade, SerbiaLay-Ekuakille, Aime, University of Lecce, ItalyLee, Jang Myung, Pusan National University, Korea SouthLee, Jun Su, Amkor Technology, Inc. South KoreaLei, Hua, National Starch and Chemical Company, USALi, Genxi, Nanjing University, ChinaLi, Hui, Shanghai Jiaotong University, ChinaLi, Xian-Fang, Central South University, ChinaLiang, Yuanchang, University of Washington, USALiawruangrath, Saisunee, Chiang Mai University, ThailandLiew, Kim Meow, City University of Hong Kong, Hong KongLin, Hermann, National Kaohsiung University, TaiwanLin, Paul, Cleveland State University, USALinderholm, Pontus, EPFL - Microsystems Laboratory, SwitzerlandLiu, Aihua, University of Oklahoma, USALiu Changgeng, Louisiana State University, USALiu, Cheng-Hsien, National Tsing Hua University, TaiwanLiu, Songqin, Southeast University, ChinaLodeiro, Carlos, University of Vigo, SpainLorenzo, Maria Encarnacio, Universidad Autonoma de Madrid, SpainLukaszewicz, Jerzy Pawel, Nicholas Copernicus University, PolandMa, Zhanfang, Northeast Normal University, ChinaMajstorovic, Vidosav, University of Belgrade, SerbiaMarquez, Alfredo, Centro de Investigacion en Materiales Avanzados,MexicoMatay, Ladislav, Slovak Academy of Sciences, SlovakiaMathur, Prafull, National Physical Laboratory, IndiaMaurya, D.K., Institute of Materials Research and Engineering, SingaporeMekid, Samir, University of Manchester, UKMelnyk, Ivan, Photon Control Inc., CanadaMendes, Paulo, University of Minho, PortugalMennell, Julie, Northumbria University, UKMi, Bin, Boston Scientific Corporation, USAMinas, Graca, University of Minho, PortugalMoghavvemi, Mahmoud, University of Malaya, MalaysiaMohammadi, Mohammad-Reza, University of Cambridge, UKMolina Flores, Esteban, Benemérita Universidad Autónoma de Puebla,MexicoMoradi, Majid, University of Kerman, IranMorello, Rosario, University "Mediterranea" of Reggio Calabria, ItalyMounir, Ben Ali, University of Sousse, TunisiaMulla, Imtiaz Sirajuddin, National Chemical Laboratory, Pune, IndiaNeelamegam, Periasamy, Sastra Deemed University, IndiaNeshkova, Milka, Bulgarian Academy of Sciences, BulgariaOberhammer, Joachim, Royal Institute of Technology, SwedenOuld Lahoucine, Cherif, University of Guelma, AlgeriaPamidighanta, Sayanu, Bharat Electronics Limited (BEL), IndiaPan, Jisheng, Institute of Materials Research & Engineering, SingaporePark, Joon-Shik, Korea Electronics Technology Institute, Korea SouthPenza, Michele, ENEA C.R., ItalyPereira, Jose Miguel, Instituto Politecnico de Setebal, PortugalPetsev, Dimiter, University of New Mexico, USAPogacnik, Lea, University of Ljubljana, SloveniaPost, Michael, National Research Council, CanadaPrance, Robert, University of Sussex, UKPrasad, Ambika, Gulbarga University, IndiaPrateepasen, Asa, Kingmoungut's University of Technology, ThailandPullini, Daniele, Centro Ricerche FIAT, ItalyPumera, Martin, National Institute for Materials Science, JapanRadhakrishnan, S. National Chemical Laboratory, Pune, IndiaRajanna, K., Indian Institute of Science, IndiaRamadan, Qasem, Institute of Microelectronics, SingaporeRao, Basuthkar, Tata Inst. of Fundamental Research, IndiaRaoof, Kosai, Joseph Fourier University of Grenoble, FranceReig, Candid, University of Valencia, SpainRestivo, Maria Teresa, University of Porto, PortugalRobert, Michel, University Henri Poincare, FranceRezazadeh, Ghader, Urmia University, IranRoyo, Santiago, Universitat Politecnica de Catalunya, SpainRodriguez, Angel, Universidad Politecnica de Cataluna, SpainRothberg, Steve, Loughborough University, UKSadana, Ajit, University of Mississippi, USASadeghian Marnani, Hamed, TU Delft, The NetherlandsSandacci, Serghei, Sensor Technology Ltd., UKSchneider, John K., Ultra-Scan Corporation, USASeif, Selemani, Alabama A & M University, USASeifter, Achim, Los Alamos National Laboratory, USASengupta, Deepak, Advance Bio-Photonics, IndiaShearwood, Christopher, Nanyang Technological University, SingaporeShin, Kyuho, Samsung Advanced Institute of Technology, KoreaShmaliy, Yuriy, Kharkiv National Univ. of Radio Electronics, UkraineSilva Girao, Pedro, Technical University of Lisbon, PortugalSingh, V. R., National Physical Laboratory, IndiaSlomovitz, Daniel, UTE, UruguaySmith, Martin, Open University, UKSoleymanpour, Ahmad, Damghan Basic Science University, IranSomani, Prakash R., Centre for Materials for Electronics Technol., IndiaSrinivas, Talabattula, Indian Institute of Science, Bangalore, IndiaSrivastava, Arvind K., Northwestern University, USAStefan-van Staden, Raluca-Ioana, University of Pretoria, South AfricaSumriddetchka, Sarun, National Electronics and Computer TechnologyCenter, ThailandSun, Chengliang, Polytechnic University, Hong-KongSun, Dongming, Jilin University, ChinaSun, Junhua, Beijing University of Aeronautics and Astronautics, ChinaSun, Zhiqiang, Central South University, ChinaSuri, C. Raman, Institute of Microbial Technology, IndiaSysoev, Victor, Saratov State Technical University, RussiaSzewczyk, Roman, Industrial Research Inst. for Automation andMeasurement, PolandTan, Ooi Kiang, Nanyang Technological University, Singapore,Tang, Dianping, Southwest University, ChinaTang, Jaw-Luen, National Chung Cheng University, TaiwanTeker, Kasif, Frostburg State University, USAThumbavanam Pad, Kartik, Carnegie Mellon University, USATian, Gui Yun, University of Newcastle, UKTsiantos, Vassilios, Technological Educational Institute of Kaval, GreeceTsigara, Anna, National Hellenic Research Foundation, GreeceTwomey, Karen, University College Cork, IrelandValente, Antonio, University, Vila Real, - U.T.A.D., PortugalVaseashta, Ashok, Marshall University, USAVazquez, Carmen, Carlos III University in Madrid, SpainVieira, Manuela, Instituto Superior de Engenharia de Lisboa, PortugalVigna, Benedetto, STMicroelectronics, ItalyVrba, Radimir, Brno University of Technology, Czech RepublicWandelt, Barbara, Technical University of Lodz, PolandWang, Jiangping, Xi'an Shiyou University, ChinaWang, Kedong, Beihang University, ChinaWang, Liang, Pacific Northwest National Laboratory, USAWang, Mi, University of Leeds, UKWang, Shinn-Fwu, Ching Yun University, TaiwanWang, Wei-Chih, University of Washington, USAWang, Wensheng, University of Pennsylvania, USAWatson, Steven, Center for NanoSpace Technologies Inc., USAWeiping, Yan, Dalian University of Technology, ChinaWells, Stephen, Southern Company Services, USAWolkenberg, Andrzej, Institute of Electron Technology, PolandWoods, R. Clive, Louisiana State University, USAWu, DerHo, National Pingtung Univ. of Science and Technology, TaiwanWu, Zhaoyang, Hunan University, ChinaXiu Tao, Ge, Chuzhou University, ChinaXu, Lisheng, The Chinese University of Hong Kong, Hong KongXu, Tao, University of California, Irvine, USAYang, Dongfang, National Research Council, CanadaYang, Wuqiang, The University of Manchester, UKYang, Xiaoling, University of Georgia, Athens, GA, USAYaping Dan, Harvard University, USAYmeti, Aurel, University of Twente, NetherlandYong Zhao, Northeastern University, ChinaYu, Haihu, Wuhan University of Technology, ChinaYuan, Yong, Massey University, New ZealandYufera Garcia, Alberto, Seville University, SpainZakaria, Zulkarnay, University Malaysia Perlis, MalaysiaZagnoni, Michele, University of Southampton, UKZamani, Cyrus, Universitat de Barcelona, SpainZeni, Luigi, Second University of Naples, ItalyZhang, Minglong, Shanghai University, ChinaZhang, Qintao, University of California at Berkeley, USAZhang, Weiping, Shanghai Jiao Tong University, ChinaZhang, Wenming, Shanghai Jiao Tong University, ChinaZhang, Xueji, World Precision Instruments, Inc., USAZhong, Haoxiang, Henan Normal University, ChinaZhu, Qing, Fujifilm Dimatix, Inc., USAZorzano, Luis, Universidad de La Rioja, SpainZourob, Mohammed, University of Cambridge, UKSensors & Transducers Journal (ISSN 1726-5479) is a peer review international journal published monthly online by International Frequency Sensor Association (IFSA).Available in electronic and on CD. Copyright 2009 by International Frequency Sensor Association. All rights reserved.

Sensors & Transducers JournalContentsVolume 115Issue 4April 2010www.sensorsportal.comISSN 1726-5479Research ArticlesRole of MEMS in Biomedical Application: A ReviewHimani Sharma, P. A. Alvi, S. Dalela and J. Akhtar .1Novel Pressure Sensor for Aerospace PurposesT. Beutel, M. Leester-Schädel, P. Wierach, M. Sinapius and S. Büttgenbach .11Design and Implementation of an Embedded Digital Throwing System Based on MEMSMultiaxial AccelerometerZhen Gao and Dan Zhang.20On the Modeling of a MEMS Based Capacitive Accelerometer for Measurement of TractorSeat VibrationM. Alidoost, G. Rezazadeh, M. Hadad-Derafshi .29Optimization of Contact Force and Pull-in Voltage for Series based MEMS SwitchAbhijeet Kshirsagar, S. P. Duttagupta, S. A. Gangal. .43Fully On-chip High Q Inductors Based on MicrotechnologiesKriyang Shah, Nazuhusna Khalid, Jugdutt Singh, Hai P. Le, John Devlin and Zaliman Sauli.48A Combined Thermo-Electrostatic MEMS-Based Switch with Low Actuation VoltageParisa Mahmoudi, Habib Badri Ghavifekr, Esmail Najafiaghdam. .61Output Force Enhancement of Scratch Drive Actuator in Low-Voltage Region by UsingFlexible JointShawn Chen, Chiawei Chang and Wensyang Hsu .71Electroplated Nickel Micromirror ArrayMahmoud Almasri and Albert B. Frazier .83Pull-In Phenomenon Investigation in Nonlinear Electromechanical Coupled Systemby Distributed Model Frequency Analysis MethodAhmadali Tahmasebi-Moradi, Fatemeh Abdolkarimzadeh and Ghader Rezazadeh.92Generic Compact Model of Double-Gate MOSFETs Applicable to Different Operation Modesand ChannelsXingye Zhou, Jian Zhang, Lining Zhang, Chenyue Ma, Xing Zhang, Jin He and Mansun Chan.108The Design, Fabrication and Characterization of Nematic Liquid Crystals based Chemicaland Biological Sensors with Electroplated MicrostructuresJun Namkung and Robert G. Lindquist .116Analytic Calculation of Forces and Torques on a Silicon Die under Fluidic Self-alignmentR. C. Woods .124

Silicon Die Self-alignment on a Wafer: Stable and Unstable ModesJean Berthier, Kenneth Brakke, François Grossi, Loïc Sanchez, Léa DI Cioccio.135A Method to Improve the SGADER Process and Fabricate Ultra-thick Proof Mass InertialSensors under the Same DRIE TechniqueHaifeng Dong, Jianli Li.151Design of Novel Paper-based Inkjet Printed Rounded Corner Bowtie Antenna for RFIDApplicationsYasar Amin, Julius Hållstedt, Hannu Tenhunen, Li-Rong Zheng.160Authors are encouraged to submit article in MS Word (doc) and Acrobat (pdf) formats by e-mail: editor@sensorsportal.comPlease visit journal’s webpage with preparation instructions: .htmInternational Frequency Sensor Association (IFSA).

Sensors & Transducers Journal, Vol. 115, Issue 4, April 2010, pp. 83-91Sensors & TransducersISSN 1726-5479 2010 by IFSAhttp://www.sensorsportal.comElectroplated Nickel Micromirror Array1Mahmoud Almasri and 2Albert B. Frazier1Department of Electrical and Computer Engineering, University of Missouri,Columbia, MO 652112Department of Electrical and Computer Engineering, Georgia Institute of Technology,Atlanta, GA 30332E-mail: almasrim@missouri.eduReceived: 5 February 2010 /Accepted: 20 April 2010 /Published: 27 April 2010Abstract: This paper presents the design, fabrication and testing of metallic micromirror array for usein Metal-Organic Molecular Beam Epitaxy system (MOMBE) to define the device structure and henceeliminate the need for etching and lithography. The micromirror is structurally composed of primarilyelectroplated nickel, a mechanically durable material with controllable residual stress. The high glasstransition temperature of nickel allows it to be used without causing any contamination to the epitaxialsystems or to the deposited materials. Each mirror is designed with hexagonal shape with a diameter of0.5 mm to provide high fill factor. The torsion beams were designed with a straight bar and serpentineshape in order to optimize the voltage necessary to tilt the micromirror by 10o. The fabricatedmicromirrors with a plate thickness of 2.5 µm and torsion beam length of 80 µm, were rotated 6.84o byapplying 65 V. Copyright 2010 IFSA.Keywords: Micromirror, Electroplated nickel, Metallic micromirror1. IntroductionSeveral groups have successfully demonstrated scanning micromirror arrays using various actuationmechanisms, including electrostatic [1-4], piezoelectric [6, 7], magnetic [8] and thermal [9, 10].Electrostatic actuation was selected for use here due to its fast switching time, low powerconsumptions, low production cost, simple electronics, and simple fabrication and integration.Micromachined electrostatic micromirrors have also been used in many applications which includeprojection display [11, 12], maskless lithography [13, 14], optical scanner [15], laser printer [16],microconfocal microscopy, [4], switches and optical cross-connects, variable optical attenuator and83

Sensors & Transducers Journal, Vol. 115, Issue 4, April 2010, pp. 83-91optical/add drop multiplexer for telecommunication networks [1, 17, 18]. On the other hand, thepiezoelectric actuation requires high voltage to rotate the micromirror with large angle. The magneticactuation can achieve large rotation angle, e.x., 16.1o. However, the device occupies a large area;therefore, it cannot be used for large array format [8]. The micromirror arrays have been fabricatedusing bulk and surface micromachining of single crystal silicon (SCS) [19, 20], bulk micromachiningof silicon [21], deep reactive ion etching (DRIE) of silicon on insulator (SOI) [1, 22-24] and surfacemicromachining of polycrystalline silicon [25].Several groups have successfully demonstrated micromirror array with high fill factor using theelectrostatic actuation mechanism. The digital micromirror device (DMD), the core of DLP, is an arrayof aluminum micromirrors, each with an area of 16 16 µm2, monolithically fabricated over an array ofSRAM cells. Each mirror can rotate up to 10o. Although this technology has shown superiority overother micromirror structures, its complicated design reduces the yield which results in an expensivearray [11, 28]. Other groups have fabricated micromirror arrays (16 16 µm2) with high fill factor usingmembrane transfer bonding technology. In this case a thin mono-crystalline silicon layer is transferredfrom silicon on insulator (SOI) wafer to a target wafer using low temperature adhesive bonding. In thefirst group (Niklaus and colleagues), the micromirror lost a large portion of its area due to the torsionbeam design; no testing results were reported [29]. Bakke and colleagues fabricated the micromirror tofit a specific application. In this case, the displacement is only 62 nm, which correspond to a rotationangle less than 1o [30]. A third group (Jeon and colleagues) developed micromirror with high fillfactor of 91 %. In this case, the micromirror is supported by three anchors located underneath themirror plate and the voltage required to rotate the mirror by 6o is 57 V [31]. Tsai and colleaguesdeveloped a two axis optical scanner linear array with a fill factor as high as 96 %. The torsion beamsare fabricated underneath the mirror plate. The achieved rotation angle is 4.4o [32]. In this paper,micromirror arrays are fabricated using electroplated nickel and surface micromachining. Themicromirror array will be used to project the desired image onto a GaAs wafer surface inside aMOMBE system. It will reflect the deep ultra-violet (DUV) light through the deposition gases to theGaAs wafer. The DUV is used to preferentially break GaN bonds allowing Ga to desorb from thesurface, thus adjusting composition via selective photodesorption and hence partially eliminating exsitu etching and lithography. Other examples can be constructed for the oxide, nitride, arsenide,phosphide, and antimonide material systems among others showing the versatility of the approach.2. Design and ModelingThe micromirror consists of a nickel electroplated membrane that is connected to the address lines on asilicon substrate via two nickel electroplated posts. Fig. 1 shows schematics of the electrostaticmicromirrors with two torsion beam design, straight bar and serpentine shape. The micromirrors aredesigned with several arrays, 5 5, 16 16, and 1 16 pixels. Metal addressing lines and bottomelectrodes are formed on the silicon substrate below the mirror plate. The 16 16 micromirror array isindividually addressed by rows and columns fabricated from two metal layers (gold) separated byoxide layer while the 5 5 and 1 16 micromirror arrays are individually addressed by a single metallayer (gold). To actuate the mirror, a voltage is applied between the mirror membrane and the bottomelectrode. Each micromirror is designed with a hexagonal shape and has a diameter of 500 µm. Thehexagonal shape will allow the mirror array to have high fill factor in comparison to a circular shapearray. Each mirror is also designed with circular dimples in order to control the maximum tilt angleand prevent an electrical short circuit between the mirror and the bottom electrode (Fig. 1).Finite element analysis using ANSYS/Multiphysics simulation package has been employed to determine themicromirror geometries and to provide accurate prediction of their static and dynamic performance. A reducedorder modeling (ROM element type 144) method is used in order to efficiently solve coupled-field problemsinvolving flexible (micromirror) structures. Both the static and dynamic behavior of the torsional84

Sensors & Transducers Journal, Vol. 115, Issue 4, April 2010, pp. 83-91micromirror have been investigated using the proposed model. The structural and electrical domainswere modeled using solid45 and solid122 elements. In this model, an input text file is used where thedesign parameters can be easily changed. The torsion beams are designed with either a serpentine andstraight bar geometry. The serpentine beam has longer length and is less sensitive to the beam widththan the straight bar beams. Therefore, a lower actuation voltage is achieved with the serpentine type.The two models show that a voltage of 130 V and 210 V, respectively, are required to rotate the mirrorby . 1. The 3-D view of torsional micromirror geometries with straight bar and serpentine shape beams.The micromirror consists of a nickel electroplated surface, torsion beams, dimple and anchors.The bottom electrode is fabricated from sputtered gold.A)Nodal Displacement (µm)Nodal Displacement (µm)The micromirror becomes unstable at certain tilting angle commonly referred to as “snap-down” anglewhere the electrostatic force (in case of serpentine beam is 130 V) overcomes the mechanical force andthe movable mirror snaps abruptly to the fixed electrode plate, when the applied voltage is increasedabove a 130 V. The snap down behavior can be prevented if the mirror rotation is limited to one-thirdto one-half of the mirror touch-down angle [27]. Therefore, the air gap underneath the mirror must beat least 3 times thicker than the air gap needed to achieve the desired physical -swing angle. Theresults are plotted in Fig. 2. The structural displacements in the Z-direction for the two models areshown in Fig. 3. The length, width and thickness of the torsion beams for the 500 µm diameter mirrorare shown in Table 1. The micromirror with the serpentine torsion beam is operated at a resonantfrequency of 2.2 kHz as shown in Fig. 4.Voltage (V)B)Voltage (V)Fig. 2. Characteristics of the micromirror with a) a serpentine and b) straight bar beam.85

Sensors & Transducers Journal, Vol. 115, Issue 4, April 2010, pp. 83-91Nodal SolutionNodal SolutionSTEP 2STEP 2Sub 1Sub 1TIME 2TIME 2Fig. 3. The structural displacements in the Z-direction of the micromirror with (a) a serpentine shape;and (b) straight bar torsion beam.Table 1. The serpentine and straight bar torsion beam geometries and the simulation results.SerpentineStraightLength( m)300120Width( m)104Thickness( m)22Voltage(V)140210Res. Frequency(Hz)22002200Fig. 4. Resonant frequency as a function of modal amplitude of the micromirror with a serpentineshape torsion beam.3. FabricationThe micromirrors are fabricated with hexagonal shape and with a diameter of 0.50 mm using metalsputtering, nickel electroplating, photoresist sacrificial layer, surface micromachining, andphotolithography. In this paper, the fabricated micromirrors can rotate up to 6.84o, which is smallerthan the designed ones (rotation angle 10o). In future fabrication, the photoresist sacrificial layer will86

Sensors & Transducers Journal, Vol. 115, Issue 4, April 2010, pp. 83-91be increased to allow the mirror to rotate up to 10o. This will require changing the serpentine torsionbeam dimensions in order to keep the actuation voltage low. Fig. 5 shows the micromirror arrayfabrication sequence. The device fabrication steps are described as follows. Initially, conventional ICPsilicon etching is used to etch 5 µm deep trenches, 40 40 µm2, into a silicon wafer at locationscorresponding to the micromirror anchors (Fig. 5a). This step enables fabrication of nickel anchorswith excellent adhesion to the substrate (seed layer) because of increasing the adhesion surface area.To make this process CMOS compatible, this step can be eliminated. The wafer is then cleaned withacetone, methanol and DI water followed by pirhana etch for 5 min. The wafer is thermally oxidized at1100 oC to grow a 300 nm thick SiO2 for insulation. Next, four layers of titanium (Ti), Copper (Cu),chromium (Cr) and gold (Au) thin films were sputter deposited to serve as seed layer for the mirroranchors as well as the bottom electrode. The measured

Sensors & Transducers Volume 115, Issue 4, April 2010 www.sensorsportal.com ISSN 1726-5479 Editors-in-Chief: professor Sergey Y. Yurish, tel.: 34 696067716, fax: 34 93 4011989, e-mail: editor@sensorsportal.com Editors for Western Europe Meijer, Gerard C.M., Delft University of Technology, The Netherlands

Related Documents:

PSI AP Physics 1 Name_ Multiple Choice 1. Two&sound&sources&S 1∧&S p;Hz&and250&Hz.&Whenwe& esult&is:& (A) great&&&&&(C)&The&same&&&&&

Argilla Almond&David Arrivederci&ragazzi Malle&L. Artemis&Fowl ColferD. Ascoltail&mio&cuore Pitzorno&B. ASSASSINATION Sgardoli&G. Auschwitzero&il&numero&220545 AveyD. di&mare Salgari&E. Avventurain&Egitto Pederiali&G. Avventure&di&storie AA.&VV. Baby&sitter&blues Murail&Marie]Aude Bambini&di&farina FineAnna

The program, which was designed to push sales of Goodyear Aquatred tires, was targeted at sales associates and managers at 900 company-owned stores and service centers, which were divided into two equal groups of nearly identical performance. For every 12 tires they sold, one group received cash rewards and the other received

College"Physics" Student"Solutions"Manual" Chapter"6" " 50" " 728 rev s 728 rpm 1 min 60 s 2 rad 1 rev 76.2 rad s 1 rev 2 rad , π ω π " 6.2 CENTRIPETAL ACCELERATION 18." Verify&that ntrifuge&is&about 0.50&km/s,∧&Earth&in&its& orbit is&about p;linear&speed&of&a .

theJazz&Band”∧&answer& musical&questions.&Click&on&Band .

Other examples of sensors Heart monitoring sensors "Managing Care Through the Air" » IEEE Spectrum Dec 2004 Rain sensors for wiper control High-end autos Pressure sensors Touch pads/screens Proximity sensors Collision avoidance Vibration sensors Smoke sensors Based on the diffraction of light waves

6" syl 4" syl 12" swgl @ 45 & 5' o.c. 12" swchl 6" swl r1-1 ma-d1-6a 4" syl 4" syl 2' 2' r3-5r r4-7 r&d 14.7' 13' cw open w11-15 w16-9p ma-d1-7d 12' 2' w4-3 moonwalks abb r&d r&d r&d r&d r&d r&d ret ret r&d r&d r&d r&d r&d 12' 24' r&d ma-d1-7a ma-d1-7b ret r&d r&d r5-1 r3-2 r&d r&r(b.o.) r6-1r r3-2 m4-5 m1-1 (i-195) m1-1 (i-495) m6-2l om1-1 .

Pressure Systems, Inc. KPSI Level and Pressure Transducers User’s Manual i www.PressureSystems.com Our Company Pressure Systems is an ISO9001:2000 certified U.S. manufacturer of submersible and non-submersible (above ground) pressure transducers for environmental, industrial and municipal applications.File Size: 1MBPage Count: 34Explore further1% BFSL Submersible Level Transducer KPSI 700 Series .www.te.comKPSI Transducers, Pressure Systems, Inc. WQPwww.wqpmag.comKPSI Submersible Pressure Transducers Available Online .www.te.comRecommended to you b