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MICROFABRICATED ELECTROHYDRODYNAMIC PUMPS

SENSORS AND ACTUATORS A-PHYSICAL 1990年第1-3期21卷 193-197页

作者： BART, SF TAVROW, LS MEHREGANY, M LANG, JH Laboratory for Electromagnetic and Electronic Systems Microsystems Technology Laboratory Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 U.S.A.

Pumping is often cited as a general application which motivates the development of microfabricated motors and other actuators. In that spirit, this paper studies microfabricated electrohydrodynamic fluid pumps. In electrohydrodynamic (EHD) pumping, fluid forces are generated by the interaction of electric fields and charges in the fluid. In contrast to forces generated by mechanical pumping using an impeller or bellows, EHD pumping requires no moving parts and consequently offers the possibility of simplified fabrication and high reliability. This paper discusses electrohydrodynamic pumping and issues concerning its use in micronsize scale systems. The fundamental operating principles of the EHD pump are outlined and examples of configurations which meet the requirement for inducing free electric charge are shown. The possible performance achievable in micron size-scale regimes is indicated. Issues concerning fluid conductivity, instability and surface tension are addressed. A microfabricated structure which demonstrates the EHD pumping of a highly insulating silicone oil is described. The structure consists of an array of 10 μm by 235 μm highly doped, LPCVD polycrystalline silicon electrodes patterned over silicon nitride. The electrode array is excited with a traveling wave of electric potential. Pumping results are qualitatively described. This paper describes a study of electrohydrodynamic pumping, including issues concerning its application to micron size-scale systems. The fundamental operating principles of EHD pumps are outlined and the possible performance achievable in micron size-scale regimes is indicated. Surface and bulk instabilities are addressed. Finally, the preliminary results of an EHD pumping experiment with a microfabricated structure are described. A practical requirement for EHD pumping is the induction of free electric charge in the volume of the fluid to be pumped or on its interface with another material. Charge accumulation on a material

关键词： Pumps

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Integrating semiconductor process design and manufacture using a unified process flow representation

Integrating semiconductor process design and manufacture usi...

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International Conference on computer Integrated Manufacturing

作者： M.B. McIlrath D.S. Boning Microsystems Technology Laboratories Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA

Concepts and data structures which can be used to allow effective linkage between manufacturing and design activities and hence facilitate improved process development are proposed. Central to the approach is the use of a common representation of the manufacturing process flow, used throughout the life-cycle of the process, including conceptual design, simulation, manufacturing, analysis, and maintenance. The overall architecture provides for the incorporation of models of the manufacturing equipment as well as idealized process models in a coherent way to support flexible, portable semiconductor-manufacturing processes. The authors identify the most important aspects of such a process-flow representation and describe the role of the representation in the computer-integrated manufacturing system in use in their semiconductor IC fabrication facility.< >

关键词： Process design Manufacturing processes Semiconductor device manufacture Virtual manufacturing Semiconductor process modeling Data structures Couplings Analytical models computer architecture Flexible manufacturing systems

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Friction and wear in microfabricated harmonic side-drive motors

Friction and wear in microfabricated harmonic side-drive mot...

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IEEE Workshop on Solid-State Sensor and Actuator

作者： M. Mehregany S.D. Senturia J.H. Lang Microsystems Technology Laboratories Laboratory for Electromagnetic and Electronic Systems Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA

Polysilicon variable-capacitance rotary harmonic side-drive micromotors and results from operational and frictional studies of these motors are described. Quantitative studies of wear under electric excitation are also reported. Voltages as low as 26 V across 1.5- mu m gaps are sufficient for operation. Frictional force estimates of 0.15 mu N at the bushings and 0.04 mu N in the bearings are obtained from measurements of stopping voltages. Extended operation of these motors to near 100 million wobble cycles at excitation frequencies of 10000 r.p.m. and 25000 r.p.m. for operational durations of 150 h and 71 h, respectively, are studied. The results indicate that bearing wear is significant and results in changes in the gear ratio of the motors by as much as 20%. Typical gear ratios are near 90 at the start of motor operation and decrease to about 70 as the bearings wear out.< >

关键词： Friction Micromotors Rotors Insulators Stators Contacts Force measurement Gears Micromechanical devices Testing

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A CAD architecture for microelectromechanical systems

A CAD architecture for microelectromechanical systems

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IEEE International Conference on Micro Electro Mechanical Systems

作者： F. Maseeh R.M. Harris S.D. Senturia MIT Cambridge MA USA Department of Electrical Engineering and Computer Science Microsystems Technology Laboratories Massachusetts Institute of Technology Cambridge MA USA

A CAD architecture for microelectromechanical systems is presented in which conventional mask layout and process simulation tools are linked to three-dimensional mechanical CAD and finite-element tools for analysis and simulation. The architecture is exercised by an elementary example on the stress-induced curvature of an oxidized silicon wafer. An architecture for an object-oriented material property simulator in which material properties and their process dependence are stored and are accessed based on the specific process conditions is also presented.< >

关键词： Microelectromechanical systems Object oriented modeling Material properties Solid modeling Analytical models Predictive models Packaging Computational modeling computer simulation Silicon

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A high frequency fully differential BiCMOS operational amplifier

A high frequency fully differential BiCMOS operational ampli...

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Custom Integrated Circuits Conference (CICC)

作者： A.N. Karanicolas K.K. O J.Y. Wang H.-S. Lee R.L. Reif Microsystems Technology Laboratory Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA

A BiCMOS differential operational amplifier designed for use in switched-capacitor circuits is presented. This BiCMOS op-amp offers an infinite input resistance, a DC gain of 100 dB, a unity-gain frequency of 90 MHz with 45 degrees phase margin, and a slew rate of 150 V/ mu s. The op-amp is unity gain stable with 7 pF of capacitive loading. The circuit is operated from a +or-5-V power supply and dissipates 125 mW. The op-amp is integrated in the 3.0-GHz, 2-RGmm MIT BiCMOS process with an active die area of 1.0 mm*1.2 mm.< >

关键词： Frequency BiCMOS integrated circuits Differential amplifiers Operational amplifiers Analog circuits Switched capacitor circuits Switching circuits Transconductance CMOS logic circuits Epitaxial layers

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A microfabricated three-degree-of-freedom parallel mechanism

A microfabricated three-degree-of-freedom parallel mechanism

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IEEE International Conference on Micro Electro Mechanical Systems

作者： F. Behi M. Mehregany K.J. Gabriel Robotics Research Department Machine Perception Research Department AT and T Bell Laboratories Inc. Holmdel NJ USA Microsystems Technology Laboratories Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA Tokyo Japan

A microfabricated, three-degree-of-freedom, passive, closed-chain, planar mechanism with the potential for low-torque precision positioning applications is presented. A parallel-link mechanism design is selected rather than a serial-link implementation, since parallel-link mechanisms can operate with stationary actuators and are more rigid than their serial counterparts. Polysilicon surface micromachining is used to fabricate a mechanism which has a total area of 0.13 mm/sup 2/ and a workspace of approximately 0.01 mm/sup 2/. The fabrication process for the mechanism is described, identifying the effect on device performance of constraints imposed by the microfabrication; most notably joint clearances, component nonplanarity, and residual-stress-induced linkage deformations. The requisite formulations for the kinematics and dynamics of the device are presented which, in conjunction with the documented measurements of friction on structures of similar geometry and material, indicate that the dominant torque loads are due to friction.< >

关键词： Fabrication Micromotors Couplings Kinematics Actuators Friction Silicon Micromachining Torque measurement Appropriate technology

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Operation of microfabricated harmonic and ordinary side-drive motors

Operation of microfabricated harmonic and ordinary side-driv...

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IEEE International Conference on Micro Electro Mechanical Systems

作者： M. Megregany P. Nagarkar S.D. Senturia J.H. Lang Dept. of Electr. Eng. & Comput. Sci. MIT Cambridge MA USA Microsystems Technology Laboratories Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA Laboratory for Electromagnetic and Electronic Systems Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA

A variable-capacitance harmonic side-drive motor is presented and the operation of this motor and ordinary variable-capacitance side-drive motors without the need for air-levitation assist is reported. Native oxide formation on motor polysilicon surfaces, resulting from the clamping of the rotor to the shield beneath it, is identified as the cause of motor operational failure. With proper release and testing directed at minimizing this oxide formation, the motors can be readily operated. Operational characteristics of the micromotors, including the role of rotor electric shielding, speed, and frictional effects, are studied. For the side-drive motors, measurements of stopping and starting voltages indicate that the drive torque required to sustain motor operation is 5-7 pN-m, while that required to initiate motor operation after a 30 second rest is nearly twice as high.< >

关键词： Micromotors Rotors Contacts Clamps Stators laboratories Testing Electrostatic levitation Torque measurement Voltage

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三个微加工可变电容式马达的研究

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电子器件 1990年第3期13卷 49-50页

作者： M.MEHREGANY S.F.BART L.S.TAVROW J.H.LANG S.D.SENTURIA M.F.SCHLECHT 李明祥 Microsystems Microsystems Techno’ogy Laboratories Dapartment of Electrical Engineering and Computer ScienceMassachusetts Institute of TechnologyCambridgeMA 02139(U.S.A

本文讨论了三种可变电容式电动马达的工作原理、设计和微细加工.它们分别是顶部驱动式、侧向驱动式和调谐侧向驱动式三种.这些微型马达的各自优点与不足之处也一并作了讨论.本文中讨论的这些微型马达都是通过表面微细加工的方式制得的.... 详细信息

本文讨论了三种可变电容式电动马达的工作原理、设计和微细加工.它们分别是顶部驱动式、侧向驱动式和调谐侧向驱动式三种.这些微型马达的各自优点与不足之处也一并作了讨论.本文中讨论的这些微型马达都是通过表面微细加工的方式制得的.高掺杂的LPCVD多晶硅用作结构部分,牺牲层采用LPCVD氧化硅,而LPCVD氮化硅用作电绝缘.整个加工过程包括两次多晶硅淀积,两次氧化硅及两次氮化硅淀积等步骤.

关键词：可变电容式微型马达微电机

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Comparative analysis of RDBMS and OODBMS: a case study

Comparative analysis of RDBMS and OODBMS: a case study

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IEEE Compcon

作者： M.A. Ketabchi S. Mathur T. Risch J. Chen Department of Electrical Engineering & Computer Sciences Santa Clara University Santa Clara CA USA Data Management Systems Division Hewlett Packard Company Cupertino CA USA Database Technology Department/Stanford Science Center Hewlett Packard Laboratories Palo Alto CA USA Corporate Product Generation Process Department Hewlett Packard Company Palo Alto CA USA

The underlying hypothesis of the case study described is that the development, implementation, operations, and maintenance of large, complex, data-intensive applications, such as computer-integrated manufacturing, can be simplified through the use of object-oriented database management systems (DBMSs). The objective of the case study is to verify this hypothesis. The approach is to prototype selected representative components of a computer-integrated-manufacturing system; these components have been developed on top of a relational DBMS, using an object-oriented DBMS, called Iris. The fundamental elements of the data model of Iris are objects, types, and functions. An Iris object is represented by a unique identifier. Each object is associated with at least one type. This association supports classification. An object is said to be the instance of the types with which it has classification associations. The results of the study illustrate that the object-oriented prototype has a superior schema, is capable of providing convenient access to information, and is easier to extend and maintain.< >

关键词： computer aided software engineering Object oriented modeling Transaction databases Data models computer integrated manufacturing Prototypes Database languages laboratories Milling machines Application software

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MONITORING THE CURE OF A COMPOSITE MATRIX RESIN WITH MICRODIELECTROMETRY

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POLYMER engineering AND science 1989年第5期29卷 290-294页

作者： BIDSTRUP, WW SENTURIA, SD Microsystems Technology Laboratories Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge Massachusetts 02139

This paper presents a study of the cure of glass and graphite fiber epoxy composites using dielectric monitoring techniques. Initial results reported here deal with the neat resin and the relationship between its cond... 详细信息

关键词： Composite Materials

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