Pub Date : 2003-09-01DOI: 10.1142/S1465876303001654
K. L. Zhang, S. Chou, S. Ang, X. S. Tang, J. S. Phang
A novel micropropulsion system is described for high-accuracy station keeping, attitude control and speed adjusting of microspacecraft. The proposed solid propellant microthruster is composed of two layers bonded together. One layer is a silicon layer, which contains a microchamber, a micronozzle and a 30-micron slot. The specific solid propellant is loaded in the microhamber for combustion. The convergent-divergent micronozzle is used to accelerate the combustion gas to produce thrust. The slot is employed to insert the special ignition wire to ignite the solid propellant. The other layer is a glass layer, which is bonded onto the silicon layer to form 3-D microthruster. Numerical investigations have been carried out before the fabrication. The thrust ranging from 1 mN to 10 mN is produced depending of on different geometries. Single microthrusters and microthruster layers have been fabricated successfully using MEMS technologies.
{"title":"Investigation Of Solid Propellant Microthrusters","authors":"K. L. Zhang, S. Chou, S. Ang, X. S. Tang, J. S. Phang","doi":"10.1142/S1465876303001654","DOIUrl":"https://doi.org/10.1142/S1465876303001654","url":null,"abstract":"A novel micropropulsion system is described for high-accuracy station keeping, attitude control and speed adjusting of microspacecraft. The proposed solid propellant microthruster is composed of two layers bonded together. One layer is a silicon layer, which contains a microchamber, a micronozzle and a 30-micron slot. The specific solid propellant is loaded in the microhamber for combustion. The convergent-divergent micronozzle is used to accelerate the combustion gas to produce thrust. The slot is employed to insert the special ignition wire to ignite the solid propellant. The other layer is a glass layer, which is bonded onto the silicon layer to form 3-D microthruster. Numerical investigations have been carried out before the fabrication. The thrust ranging from 1 mN to 10 mN is produced depending of on different geometries. Single microthrusters and microthruster layers have been fabricated successfully using MEMS technologies.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114775018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001800
Liujiang Yu, B. Tay, D. Sheeja, Y. Fu, J. Miao
The primary problem of large intrinsic compressive stress induced during the deposition of amorphous carbon (a-C) films prepared by Filtered Cathodic Vacuum Arc (FCVA) technique has been overcome by preparing the films in conjuction with high substrate pulse biasing. However, it has been observed that the stress reduction is achieved by sacrificing the mechanical properties such as hardness and Young's modulus of the films. Hence the mechanical properties of the films were studied as a function of substrate bias voltage. In addition, to demostrate these low stress films, one-micron thick, a-C membranes were fabricated by photolithography technique together with deep reactive ion etching (deep RIE) and wet KOH etching.
利用过滤阴极真空电弧(FCVA)技术制备非晶碳薄膜，克服了薄膜沉积过程中存在的固有压应力大的主要问题，并与高衬底脉冲偏置相结合。然而，已经观察到应力的减小是通过牺牲薄膜的硬度和杨氏模量等力学性能来实现的。因此，研究了薄膜的力学性能随衬底偏压的变化规律。此外，为了证明这些低应力薄膜，采用光刻技术与深度反应离子蚀刻(deep reactive ion etching, deep RIE)和湿式KOH蚀刻一起制备了1微米厚的a-C膜。
{"title":"Fabrication Of Amorphous Carbon Micro-Membranes By Deep Reactive Ion Etching Technique","authors":"Liujiang Yu, B. Tay, D. Sheeja, Y. Fu, J. Miao","doi":"10.1142/S1465876303001800","DOIUrl":"https://doi.org/10.1142/S1465876303001800","url":null,"abstract":"The primary problem of large intrinsic compressive stress induced during the deposition of amorphous carbon (a-C) films prepared by Filtered Cathodic Vacuum Arc (FCVA) technique has been overcome by preparing the films in conjuction with high substrate pulse biasing. However, it has been observed that the stress reduction is achieved by sacrificing the mechanical properties such as hardness and Young's modulus of the films. Hence the mechanical properties of the films were studied as a function of substrate bias voltage. In addition, to demostrate these low stress films, one-micron thick, a-C membranes were fabricated by photolithography technique together with deep reactive ion etching (deep RIE) and wet KOH etching.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133864994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001514
A. Liu, X. Zhang, J. Li, D. Tang
Tunable lasers have wide applications in DWDM systems to save inventory cost and to improve the optical network functionalities. The Microelectromechanical Systems (MEMS) technology has shown strong promise to miniaturize the conventional mechanical tunable lasers with adding merits of high compactness, high speed batch production and so on. In this paper, external cavity tunable diode lasers using MEMS movable mirrors and rotary gratings as the external reflectors are presented. One tunable laser of 2 mm × 1.5 mm is formed by integration of a surface-micromachined 3D mirror with a diode laser and an optical fiber. In addition, deep-etched structures such rotary gratings, circular mirror, microlens, and grooves for diode laser and fiber are illustrated to form widely tunable lasers.
可调谐激光器在DWDM系统中有广泛的应用，以节省库存成本和提高光网络的功能。微机电系统(MEMS)技术具有体积小、批量生产速度快等优点，有望使传统的机械可调谐激光器小型化。本文介绍了一种采用MEMS活动反射镜和旋转光栅作为外反射器的外腔可调谐二极管激光器。通过将表面微加工三维镜面与二极管激光器和光纤集成，形成一个2 mm × 1.5 mm的可调谐激光器。此外，深蚀刻结构，如旋转光栅，圆镜，微透镜，和凹槽的二极管激光器和光纤说明形成广泛可调谐的激光器。
{"title":"Characteristics Of Micromachined Short-External-Cavity Tunable Lasers","authors":"A. Liu, X. Zhang, J. Li, D. Tang","doi":"10.1142/S1465876303001514","DOIUrl":"https://doi.org/10.1142/S1465876303001514","url":null,"abstract":"Tunable lasers have wide applications in DWDM systems to save inventory cost and to improve the optical network functionalities. The Microelectromechanical Systems (MEMS) technology has shown strong promise to miniaturize the conventional mechanical tunable lasers with adding merits of high compactness, high speed batch production and so on. In this paper, external cavity tunable diode lasers using MEMS movable mirrors and rotary gratings as the external reflectors are presented. One tunable laser of 2 mm × 1.5 mm is formed by integration of a surface-micromachined 3D mirror with a diode laser and an optical fiber. In addition, deep-etched structures such rotary gratings, circular mirror, microlens, and grooves for diode laser and fiber are illustrated to form widely tunable lasers.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133586152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001691
K. Lian, J. C. Jiang, S. Wen, C. Liu, Z. Ling
In this work, an electroplated Ni material made from sulfuric acid-based plating solution has been studied. Differential scanning calorimetry (DSC) technique was used to study the stability of plated Ni at elevated temperatures. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to examine the microstructural changes of plated samples as a function of annealing temperature. Microhardness tests were performed to study the effects of the evolved microstructures on surface mechanical properties. The activation energy for the grain growth was determined by using isothermal kinetics analysis. In order to improve the performance of LIGA/MEMS components at high temperature, it is crucial to understand the grain coarsening processes of electroplated Ni materials at elevated temperature.
{"title":"Thermal Stability And Resulting Surface Mechanical Properties Of Electroplated Nanocrystalline Ni-Based Mems Material","authors":"K. Lian, J. C. Jiang, S. Wen, C. Liu, Z. Ling","doi":"10.1142/S1465876303001691","DOIUrl":"https://doi.org/10.1142/S1465876303001691","url":null,"abstract":"In this work, an electroplated Ni material made from sulfuric acid-based plating solution has been studied. Differential scanning calorimetry (DSC) technique was used to study the stability of plated Ni at elevated temperatures. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to examine the microstructural changes of plated samples as a function of annealing temperature. Microhardness tests were performed to study the effects of the evolved microstructures on surface mechanical properties. The activation energy for the grain growth was determined by using isothermal kinetics analysis. In order to improve the performance of LIGA/MEMS components at high temperature, it is crucial to understand the grain coarsening processes of electroplated Ni materials at elevated temperature.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"21 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125775422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001472
H. Cai, C. W. Chan, K. Ling, C. Lu, Y. X. Wang, A. Liu
In this study, a digital control system is developed for the microelectromechanical (MEMS) device - Variable Optical Attenuator (VOA). With the closed-loop control circuit, each VOA module implements the functions of power set point tracking and disturbance rejection. Moreover, this control system, with the device, entrusts the VOA module with leading performance, stability, reliability and fast dynamic response.
{"title":"A Study Of Closed-Loop Control Of Optical MEMS Device","authors":"H. Cai, C. W. Chan, K. Ling, C. Lu, Y. X. Wang, A. Liu","doi":"10.1142/S1465876303001472","DOIUrl":"https://doi.org/10.1142/S1465876303001472","url":null,"abstract":"In this study, a digital control system is developed for the microelectromechanical (MEMS) device - Variable Optical Attenuator (VOA). With the closed-loop control circuit, each VOA module implements the functions of power set point tracking and disturbance rejection. Moreover, this control system, with the device, entrusts the VOA module with leading performance, stability, reliability and fast dynamic response.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123480104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001745
C. Venkatesh, S. Pati, N. Bhat
A MEMS varactor using torsional beams for actuation is proposed. Analytical expression for electrostatic torque developed is derived. The structure is compared with existing structure for dynamic range and actuation voltage. A compensator is designed to improve the transient performance of the device.
{"title":"Torsional Mems Varactor With Low Actuation Voltage","authors":"C. Venkatesh, S. Pati, N. Bhat","doi":"10.1142/S1465876303001745","DOIUrl":"https://doi.org/10.1142/S1465876303001745","url":null,"abstract":"A MEMS varactor using torsional beams for actuation is proposed. Analytical expression for electrostatic torque developed is derived. The structure is compared with existing structure for dynamic range and actuation voltage. A compensator is designed to improve the transient performance of the device.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122506722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303002143
X. Shan, R. Maeda, T. Ikehara, Z. Wang, C. Wong
This paper presents an 8×8 optical switch consisting of a micro cantilever array. Each cantilever, with a vertical micro mirror located on one end of it, was driven by electrostatic actuation. The optical switch was fabricated using combined silicon process, electroplating and hot embossing. The optical switch, embossed with a polymer material, was aligned and assembled together with input and output optical fibers via grooves etched on a silicon substrate. Considering the fabrication process and material used, this optical switch is suitable for cost-effective mass production, and will potentially find wide applications for fiber-to-the-home communications.
{"title":"A Polymer-Based Optical Switch Fabricated Using Silicon Process, Electroplating And Micro Hot Embossing","authors":"X. Shan, R. Maeda, T. Ikehara, Z. Wang, C. Wong","doi":"10.1142/S1465876303002143","DOIUrl":"https://doi.org/10.1142/S1465876303002143","url":null,"abstract":"This paper presents an 8×8 optical switch consisting of a micro cantilever array. Each cantilever, with a vertical micro mirror located on one end of it, was driven by electrostatic actuation. The optical switch was fabricated using combined silicon process, electroplating and hot embossing. The optical switch, embossed with a polymer material, was aligned and assembled together with input and output optical fibers via grooves etched on a silicon substrate. Considering the fabrication process and material used, this optical switch is suitable for cost-effective mass production, and will potentially find wide applications for fiber-to-the-home communications.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117101259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S146587630300185X
Mechtilde Schäfer, R. Starzmann, A. Foitzik
Chemical reactions can be very complex and frequently produce undesired side products within short time spans. Investigation of such reactions necessitates in-situ measurements for analysis. We present a novel micro-reactor design enabling non-invasive and spatially highly resolved in-situ reaction analysis using Raman spectroscopy. The reactor consists of a stainless steel base containing milled channels covered with anodically bonded pyrex glass. The educt flow rate is finely controlled by a motor-driven feed pump. Monitoring of an exemplary test reaction by Raman spectroscopic means was achieved by recording spectra at various discrete sampling points along the reaction channel. The glass window allows visual observation of the channels by optical microscopy and does not affect, in contrast to infrared spectroscopy, the Raman spectroscopic signal. Taking Raman spectra along the reaction channel at different loci enabled us to determine the reaction kinetics of a fast chemical reaction.
{"title":"Chemical Microreactors For In-Situ Online Process Monitoring","authors":"Mechtilde Schäfer, R. Starzmann, A. Foitzik","doi":"10.1142/S146587630300185X","DOIUrl":"https://doi.org/10.1142/S146587630300185X","url":null,"abstract":"Chemical reactions can be very complex and frequently produce undesired side products within short time spans. Investigation of such reactions necessitates in-situ measurements for analysis. We present a novel micro-reactor design enabling non-invasive and spatially highly resolved in-situ reaction analysis using Raman spectroscopy. The reactor consists of a stainless steel base containing milled channels covered with anodically bonded pyrex glass. The educt flow rate is finely controlled by a motor-driven feed pump. Monitoring of an exemplary test reaction by Raman spectroscopic means was achieved by recording spectra at various discrete sampling points along the reaction channel. The glass window allows visual observation of the channels by optical microscopy and does not affect, in contrast to infrared spectroscopy, the Raman spectroscopic signal. Taking Raman spectra along the reaction channel at different loci enabled us to determine the reaction kinetics of a fast chemical reaction.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115447612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S146587630300171X
T. Lalinsky, M. Krnac, S. Hascik, Z. Mozolova, L. Matay, I. Kostic, P. Hrkut, J. Jakovenko, M. Husák
Design technology and characterization of new GaAs island based Micromechanical Thermal Converter (MTC) device are presented. The MTC device introduced consists of pHEMT as a microwave heater and thin film polySi/Ni resistor as a temperature sensor monolithically integrated on polyimide-fixed 1 μm thick GaAs/AlGaAs island structure. The preliminary experimental results in the device electro-thermal conversion evaluation are demonstrated.
{"title":"Micromechanical Thermal Converter Device Based On Polyimide-Fixed Island Structure","authors":"T. Lalinsky, M. Krnac, S. Hascik, Z. Mozolova, L. Matay, I. Kostic, P. Hrkut, J. Jakovenko, M. Husák","doi":"10.1142/S146587630300171X","DOIUrl":"https://doi.org/10.1142/S146587630300171X","url":null,"abstract":"Design technology and characterization of new GaAs island based Micromechanical Thermal Converter (MTC) device are presented. The MTC device introduced consists of pHEMT as a microwave heater and thin film polySi/Ni resistor as a temperature sensor monolithically integrated on polyimide-fixed 1 μm thick GaAs/AlGaAs island structure. The preliminary experimental results in the device electro-thermal conversion evaluation are demonstrated.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115109376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001885
W. Tan, Pei Ge, F. Tay, A. Loh
This paper describes a micro capacitive pressure sensor for hydrostatic tank gauging (HTG), an emerging way to accurately gauge liquid inventory and to monitor transfers in tank farms. Since industrial storage vessels are huge, the sensing element must be sufficiently thick to withstand the large pressure inside the tanks. However, a thick diaphragm is insensitive to the relatively small pressure changes brought about by variations in the fluid head. To detect small pressure changes in the presence of a high constant load, a novel three-plates structure that introduces an additional plate between the two electrodes of a parallel plate capacitive pressure is proposed. A boss ring etched below the thick top plate, which serves as the sensing element, will come into contact with the middle pate and cause it to deflect when the applied pressure crosses a pre-determined threshold. Pressure is measured by monitoring the change in capacitance between the middle plate and the insulated substrate. As the middle pl...
{"title":"Development Of A 3-Plates Capacitive Pressure Sensor","authors":"W. Tan, Pei Ge, F. Tay, A. Loh","doi":"10.1142/S1465876303001885","DOIUrl":"https://doi.org/10.1142/S1465876303001885","url":null,"abstract":"This paper describes a micro capacitive pressure sensor for hydrostatic tank gauging (HTG), an emerging way to accurately gauge liquid inventory and to monitor transfers in tank farms. Since industrial storage vessels are huge, the sensing element must be sufficiently thick to withstand the large pressure inside the tanks. However, a thick diaphragm is insensitive to the relatively small pressure changes brought about by variations in the fluid head. To detect small pressure changes in the presence of a high constant load, a novel three-plates structure that introduces an additional plate between the two electrodes of a parallel plate capacitive pressure is proposed. A boss ring etched below the thick top plate, which serves as the sensing element, will come into contact with the middle pate and cause it to deflect when the applied pressure crosses a pre-determined threshold. Pressure is measured by monitoring the change in capacitance between the middle plate and the insulated substrate. As the middle pl...","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124959914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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