• Title/Summary/Keyword: Micro-fabrication Technology

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A Study on the Passive Microvalve Applicable to Drainage Device for Glaucoma

  • Sim, Tae-Seok;Kim, Yong-Kweon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.2 no.4
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    • pp.253-258
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    • 2002
  • This paper reports the design, modeling, fabrication and measurement of passive microvalves, which are applicable to glaucoma implants. The proposed microvalves were designed using fluidic theory. The microvalves consisted of microchannels and chambers. The microchannels had a constant fluidic resistance generating a pressure difference. Six kinds of microvalves were designed using fluidic equations for laminar flow and fabricated to examine the influences of chamber size, channel length and the shape of channel cross section. The pressure difference between the designed microvalve and the fabricated microvalve was measured to be less than 4%.

Fabrication of Two One-Way Silicon Micro Valves using Boron Etch Stop Layer (붕소 식각 정지층을 이용한 두 개의 한 방향 실리콘 미세 밸브의 제작)

  • Seo, Jeong-Deok;Yang, Eui-Hyeok;Yang, Sang-Sik
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.210-212
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    • 1993
  • In this paper, a silicon microvalve has been fabricated using micromachining technology. The valve consists of the several thin silicon diaphragms which are designed to open and close depending on the pressure difference. It is supposed to pass fluids in only one direction. The thin diaphragms are fabricated by boron etch stop using an anisotropic etchant, EPW. The fabricated valve has been tested for various pneumatic pressure. According to the experimental results, the slit width of the valve increases as the pneumatic pressure increases.

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Development of High Precision Actuator for Micro Press System by Inchworm Motor (인치웜모터를 이용한 마이크로 프레스용 고정밀 구동기의 개발)

  • Choi, Jong-Pil;Nam, Kwang-Sun;Lee, Hye-Jin;Lee, Nak-Gue;Kim, Byeong-Hee
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.2
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    • pp.137-143
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    • 2009
  • This paper presents the fabrication of inchworm motor for high precision actuator system of large displacement and high force. The inchworm motor consists of a extend actuator that provides displacement of tool guide and two clamping actuators which provide the holding force. In order to avoid the PZT fracture, design of pre-load housing was conducted by flexure hinge structure, because PZT actuator has low tensile and shear. To design the pre-load housing and optimize the clamping mechanism, the static and dynamic analysis were conducted by finite element method. From these results, a prototype of the inchworm motor was fabricated and dynamic characteristic with respect to the various frequency was tested. The maximum velocity of the inchworm motor was $41.1{\mu}m/s$ at 16Hz.

The development of a variable capacitive pressure sensor for TPMS(tire pressure monitoring system) (TPMS 적용을 위한 가변 정전 용량형 압력센서 개발)

  • Choi, Bum-Koo;Kim, Do-Hyung;Oh, Jae-Geun
    • Journal of Sensor Science and Technology
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    • v.14 no.4
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    • pp.265-271
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    • 2005
  • In this study, a variable capacitive pressure sensor is fabricated for TPMS (Tire Pressure Monitoring System). This study is for developing sensors which consecutively measure the tire pressure given as 30 psi from the industrial standard. For improving non-linearity of the prior capacitive pressure sensors, it is suggested that touch mode capacitive pressure sensor be applied. In addition, initial capacitance is designed as small as possible for the conformity to the wireless sensor. ANSYS, commercial FEA package, is used for designing and simulating the sensor. The device is progressed by MEMS (Micro Electro Mechanical Systems) fabrication and packaged with PDMS. The result is obtained sensitivity, 1 pF/psi, through a pressure test. The simulation result is discrepant from experiment one. Wafer's uniformity is presumed as the main reason of discrepancy.

Bioinspired Nanoengineering of Multifunctional Superhydrophobic Surfaces

  • Choi, Chang-Hwan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.102-133
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    • 2015
  • Nature, such as plants, insects, and marine animals, uses micro/nano-textured surfaces in their components (e.g., leaves, wings, eyes, legs, and skins) for multiple purposes, such as water-repellency, anti-adhesiveness, and self-cleanness. Such multifunctional surface properties are attributed to three-dimensional surface structures with modulated surface wettability. Especially, hydrophobic surface structures create a composite interface with liquid by retaining air between the structures, minimizing the contact area with liquid. Such non-wetting surface property, so-called superhydrophobicity, can offer numerous application potentials, such as hydrodynamic drag reduction, anti-biofouling, anti-corrosion, anti-fogging, anti-frosting, and anti-icing. Over the last couple of decades, we have witnessed a significant advancement in the understanding of surface superhydrophobicity as well as the design, fabrication, and applications of superhydrophobic coatings/surfaces/materials. In this talk, the designs, fabrications, and applications of superhydrophobic surfaces for multifunctionalities will be presented, including hydrodynamic friction reduction, anti-biofouling, anti-corrosion, and anti-icing.

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Fabrication of a Superhydrophobic Water-Repellent Mesh for Underwater Sensors

  • An, Taechang
    • Journal of Sensor Science and Technology
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    • v.22 no.2
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    • pp.100-104
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    • 2013
  • A superhydrophobic mesh is a unique structure that blocks water, while allowing gases, sound waves, and energy to pass through the holes in the mesh. This mesh is used in various devices, such as gas- and energy-permeable waterproof membranes for underwater sensors and electronic devices. However, it is difficult to fabricate micro- and nano-structures on three-dimensional surfaces, such as the cylindrical surface of a wire mesh. In this research, we successfully produced a superhydrophobic water-repellent mesh with a high contact angle (> $150^{\circ}$) for nanofibrous structures. Conducting polymer (CP) composite nanofibers were evenly coated on a stainless steel mesh surface, to create a superhydrophobic mesh with a pore size of $100{\mu}m$. The nanofiber structure could be controlled by the deposition time. As the deposition time increased, a high-density, hierarchical nanofiber structure was deposited on the mesh. The mesh surface was then coated with Teflon, to reduce the surface energy. The fabricated mesh had a static water contact angle of $163^{\circ}$, and a water-pressure resistance of 1.92 kPa.

Fabrication of W-Cu Composite by Resistance Sintering under Ultrahigh Pressure

  • Kwon, Y.S.;Kim, J.S.;Zhou, Z.J.
    • Journal of Powder Materials
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    • v.10 no.3
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    • pp.181-185
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    • 2003
  • Resistance sintering under ultra-high pressure if developed to fabricate W-Cu composite containing 5 to 80v/o copper. The consolidation was carried out under pressure of 6 to 8 GPa and input power of 18 to 23 kW for 50 seconds. The densification effect and microstructure of these W-Cu composites are investigated. The effect of W particle size on ,sintering density was also studied. The micro hardness was measured to evaluate the sintering effect.

A Highly Sensitive Humidity Sensor Using a Modified Polyimide Film

  • Kim, Yong-Ho;Lee, Joon-Young;Kim, Yong-Jun;Kim, Jung-Hyun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.4 no.2
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    • pp.128-132
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    • 2004
  • This paper presents the design, fabrication sequence and measurement results of a highly sensitive capacitive-type humidity sensor using a polyimide film without hydrophobic elements. The structure of the humidity sensor is MIM (metalinsulator-metal). For a high sensitivity, a modified aromatic polyimides as a moisture absorbing layer has been synthesized instead of using general polyimides containing hydrophobic elements. The polyimide film was obtained by synthesizing and thermally polymerizing polyamic acid composed of m-pyromellitic dianhydride, phenelenediamine and dimethylacetamide. Characteristics of fabricated sensors which include sensitivity, hysteresis and stability have been measured. The measurement result shows the percent normalized capacitance change of 0.37/%RH over a range from 10 to 90%RH, hysteresis of 0.77% over the same %RH range and maximum drift of 0.25% at 50%RH. The result shows that the developed humidity sensor can be applied to evaluate a hermeticity of various sensors and actuator systems as well as micro packages.

A study on Fabrication and Characterization of Organic Light-Emitting Diodes (유기 발광 다이오드의 제작 및 특성에 관한 연구)

  • Lee, Han-Seong
    • Proceedings of the KIEE Conference
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    • 2008.11b
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    • pp.89-91
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    • 2008
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micro molecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

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Electromagnetic Vibration Transducer Using Silicon Elastic Body For Implantable Middle Ear Hearing Aid Applications (이식형 중이 보청기에 적용 가능한 Si 탄성체로 구현된 전자기 진동 트랜스듀서)

  • Lee, Ki-Chan;Lee, Se-Kyu;Park, Se-Kwang;Cho, Jin-Ho;Lee, Sang-Heun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.10
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    • pp.583-588
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    • 2000
  • This paper presents the design and fabrication of micro electromagnetic vibration silicon elastic body characterized with small size, high efficiency and selective frequency bandwidth for Bio-MENS applications, such as implantable middle ear hearing aid. The presented electromagnetic vibration transducer that composed of wounded coil, permanent magnet and 4-beam cross type elastic body is fabricated by using of micromachining technology. The fabricated transducer has experimental characteristics, that is 5 nm/mA of an energy trasfer rate at the frequency range of 100∼2800 Hz. It has a size of $2{\times}2{\times}2.5\;mm^3$.

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