• Title/Summary/Keyword: microsystems

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Technical and Economical Comparison of Micro Powder Injection Molding

  • Atre, Sundar V.;Wu, Carl L.;Hwang, Chul-Jin;Zauner, Rudolf;Park, Seong-Jin;German, Randall M.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.45-46
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    • 2006
  • In recent years, micro powder injection molding $(\mu-PIM)$ is being explored as an economical fabrication method for microcomponents in microsystems technology (MST). Technical and economic comparison was performed for $\mu-PIM$ processes. Molding experiment and simulation during the filling process were performed to evaluate several different geometries and processing conditions. The influence of material parameters and process conditions on mold filling were examined as a function of features size using microchannels as an example. It was found that the heat conductivity and viscosity of feedstock, geometry and mold temperature were the most critical parameters for complete filling of micro features.

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Fabrication and packaging techniques for the application of MEMS strain sensors to wireless crack monitoring in ageing civil infrastructures

  • Ferri, Matteo;Mancarella, Fulvio;Seshia, Ashwin;Ransley, James;Soga, Kenichi;Zalesky, Jan;Roncaglia, Alberto
    • Smart Structures and Systems
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    • v.6 no.3
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    • pp.225-238
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    • 2010
  • We report on the development of a new technology for the fabrication of Micro-Electro-Mechanical-System (MEMS) strain sensors to realize a novel type of crackmeter for health monitoring of ageing civil infrastructures. The fabrication of micromachined silicon MEMS sensors based on a Silicon On Insulator (SOI) technology, designed according to a Double Ended Tuning Fork (DETF) geometry is presented, using a novel process which includes a gap narrowing procedure suitable to fabricate sensors with low motional resistance. In order to employ these sensors for crack monitoring, techniques suited for bonding the MEMS sensors on a steel surface ensuring good strain transfer from steel to silicon and a packaging technique for the bonded sensors are proposed, conceived for realizing a low-power crackmeter for ageing infrastructure monitoring. Moreover, the design of a possible crackmeter geometry suited for detection of crack contraction and expansion with a resolution of $10{\mu}m$ and very low power consumption requirements (potentially suitable for wireless operation) is presented. In these sensors, the small crackmeter range for the first field use is related to long-term observation on existing cracks in underground tunnel test sections.

The Ecological Variables on Adolescents' Runway Impulse (청소년의 가출충동에 영향을 미치는 생태학적 변인)

  • Nam, Mi-Kyung;Lee, Kyung-Nim
    • Journal of Families and Better Life
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    • v.27 no.4
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    • pp.41-54
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    • 2009
  • This study focused on the ecological variables that affect adolescents' runway impulse. For the organisms, self-esteem, impulse control, school achievement and runway experience, for the microsystems, family, school and peer environment, for the mesosystems, family-peer relationships and family-school relationships, and for the exosystem, neighborhood environment were included. The sample consisted of 651 eleventh grade adolescents. Instruments were the Runway Impulse Scale(Nam, 2001) and Index of organisms, microsystems, mesosystems, and exosystem variables. Statistics and methods used for the analysis were Cronbach's alpha, frequency, percentage, t-test, Pearson's correlation and multiple Regression. Several major results were found from the analysis. First, no sex difference was found in adolescents' runway impulse. Second, runway impulse of male and female adolescents showed positive correlations with runway experience, parental marital conflict, dissatisfactions of school life and exposure to friends with problems behavior but negative correlations with self-esteem, impulse control, school achievement, parental support and supervision, teacher support, family-peer relationships and neighborhood environment. Female adolescents' runway impulse stowed negative correlations with family-school relationships. Third, the most important variable predicting male adolescents' runway impulse was exposure to friends with problems behavior, the most important variable for female was self-esteem.

Microfabrication of Microwave Transceivers for On-Chip Near-Field Electromagnetic Shielding Characterization of Electroplated Copper Layers (극소형 전자기파 송수신기의 제작 및 전기도금된 구리박막의 칩단위 근접 전자기장 차폐효과 분석)

  • Gang, Tae-Gu;Jo, Yeong-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.6
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    • pp.959-964
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    • 2001
  • An experimental investigation on the near-field electromagnetic loss of thin copper layers has been presented using microfabricated microwave transceivers for applications to multi-chip microsystems. Copper layers in the thickness range of 0.2$\mu$m∼200$\mu$m have been electroplated on the Pyrex glass substrates. Microwave transceivers have been fabricated using the 3.5mm$\times$3.5mm nickel microloop antennas, electroformed on the silicon substrates. Electromagnetic radiation loss of the copper layers placed between the microloop transceivers has been measured as 10dB∼40dB for the wave frequency range of 100MHz∼1GHz. The 0.2$\mu$m-thick copper layer provides a shield loss of 20dB at the frequencies higher than 300MHz, whereas showing a predominant decreases of shield loss to 10dB at lower frequencies. No substantial increase of the shield effectiveness has been found for the copper shield layers thicker that 2 $\mu$m.

Intermediate Language Translator for Execution of Java Programs in .NET Platform

  • Lee, Yang-Sun;Na, Seung-Won;Hwang, Dae-Hoon
    • Journal of Korea Multimedia Society
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    • v.7 no.6
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    • pp.824-831
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    • 2004
  • This paper presents the java bytecode-to-.NET MSIL intermediate language translator which enables the execution of the java program in .NET environments without JVM(java Virtual Machine), translating bytecodes produced by compiling java programs into MSIL codes. Java, one of the most widely used programming languages recently, is the language invented by James Gosling at Sun Microsystems, which is the next generation language independent of operating systems and hardware platforms. Java source code is compiled into bytecode as intermediate code independent of each platform by compiler, and also executed by JVM. .NET language such as C# and .NET platform in Microsoft Corp. has been developed to meet the needs of programmers, and cope with Java and JVM platform of Sun Microsystems. After compiling, a program written in .NET language is converted to MSIL code, and also executed by .NET platform but not in JVM platform. For this reason, we designed and implemented the java bytecode-to-.NET MSIL translator system for programs written in java language to be executed in the. NET platform without JVM. This work improves the execution speed of programs, enhances the productivity, and provides a environment for programmers to develop application programs without limitations of programming languages.

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