• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.52-58
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• 2000

최근 첨단 미세가공기술로 주목을 받고 있는 실리콘 마이크로머시닝 기술과 이를 기반으로 한 산업용 MEMS 개발현황을 소개한다. 전반부에서는 마이크로머시닝 기술의 종류를 소개하고 각각의 기술에 대해 기술근원, 미세가공원리와 기본 가공공정을 간략히 요약한 후 기전 집적형태의 마이크로머신과의 연계성을 고려한 시스템적인 측면에서의 기술특성을 상호 비교한다. 또한 가공의 양산성, 재현성, 조립성 측면에서 마이크로머시닝의 가공성을 조명함과 동시에 향후 발전방향을 전망한다.(중략)

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.22-29
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.25 no.2
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• pp.15-22
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.60-67
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• 1999

Micro-fabrication techniques such as lithography and LIGA processes usually require large investment and are suitable for mass production. Therefore, there is a need for a new micro-fabrication technique that is flexible and more cost effective. In this paper a novel, economical and flexible method of producing micro-pattern on silicon wafer is presented. This method relies on selective removal of mask by mechanical cutting. Then micro-pattern is produced by chemical etching. V-shaped grooved of about 3 ${\mu}m$ wide and 2 ${\mu}m$ deep has been made on ${SiO_2}m$ coated silicon wafer with this method. This method may be utilized for making microstructures in MEMS application at low cost.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1364-1369
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• 2004

New method for the design, fabrication, and calibration of micro-machined heat flux sensor has been developed. Two types of micro-machined heat flux sensor having different thicknesses of the thermal-resistance layer are fabricated using the MEMS technique. Photo-resist patterning using a chrome mask, bulk-etching and copper-nickel sputtering using a shadow mask are applied to make heat flux sensors, which are calibrated in the convection-type heat flux calibration facility. The sensitivity of the device varies with thermal-resistance layer, and hence can be used to measure the heat flux in heat-transfer phenomena.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.3
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• pp.7-12
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• 2002

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.42-42
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• 2010

전기천공(electroporation)은 세포에 nanosecond-millisecond 정도의 폭을 가지는 전기 펄스를 0.4-1.5 kV/cm 의 세기로 인가하여 세포 막 표면에 나노미터 크기의 미세한 기공을 형성하는 기술로서, 1970년대 처음 발견된 이래 수십 년 동안 다양한 생명공학 분야에 적용되어 왔다. 적절한 전기 펄스 조건 하에서 생성된 세포 막 표면의 미세 기공은 일정 시간 후 다시 사라지는 가역적 특성을 가져 이를 가역적 전기천공(reversible electroporation)이라 부르며, 주로 친수성약물, 유전자, 효소, 항체 등의 물질을 세포 내로 주입시키는 데 사용한다. 반면 이보다 강한 전기 펄스 하에 생성된 미세 기공은 사라지지 않고 결국 세포의 생명력을 잃게 하는 기전으로 작용하며, 이를 비가역 전기천공(irreversible electroporation)이라 한다. 비가역 전기천공 기술은 가역적 전기천공 측면에서는 바람직하지 않은 현상으로 인식되기도 하였으나, 최근 들어 그 장점을 이용한 기술적 접근이 이루어지고 있다. 전기천공은 주로 식품산업에서 미생물을 죽이는 기술이나 세포의 체외(in vitro) 유전자 주입 기술에 응용되어 왔으나, 현재는 암을 치료하기 위한 의학적 기술로 큰 주목을 받으며 많은 연구들이 진행되고 있고, 일부 기술은 이미 상용화 단계에 와있다. 본 발표는 전기천공의 기술적 이론적 배경과 함께 다양한 의학적 응용 기술에 대한 정보를 제공하며, 국내외 기초 및 응용 연구 동향 파악을 통해 국내 저변 확대 및 추후 발전 전망에 대해 논의 할 것이다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.135-141
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• 2003

MEMS structures generally have been fabricated using surface-machining method, but the interface failure between silicon substrate and evaporated thin film frequently takes place due to the residual stress inducing by the applied the various loads. And the very important physical property in the heated environment is the linear coefficient of thermal expansion. Therefore this paper studied the residual stress caused the thermal loads in the thin film and introduced the simple method to measure the trend of the residual stress by the indentation. Specimens were made of materials such as Al, Au and Cu and thermal load was applied repeatedly. The residual stress was measured by nano-indentation using AFM and FEA. The existence of the residual stress due to thermal load was verified by the experimental results. The indentation length of the thermal loaded specimens increased minimum 11.8％ comparing with the virgin thin film caused by tensile residual stress. The finite element analysis results are similar to indentation test.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.97-103
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• 2024

In this paper, the difference between the S-parameter and the characteristic impedance according to the structural change of the fine pitch coaxial socket was analyzed. A pitch of the probe pin was applied to 0.20mm, and ground pins of different conditions were placed on each of the five signal pins. Insertion loss and reflection loss were analyzed for the coaxial socket of normal structure and the two sockets of the proposed structure. In addition, the difference in characteristic impedance was analyzed using time domain reflectometry. Through the analysis, it was confirmed that the characteristic impedance was improved applying the new structures of the socket at the same pitch

• Journal of Life Science
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• v.33 no.3
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• pp.295-303
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• 2023

Immune and metabolic systems are important factors in maintaining homeostasis. Immune response and metabolic regulation are highly associated, so, when the normal metabolism is disturbed, the immune response changed followed the metabolic diseases occur. Likewise, obesity is highly related to immune response. Obesity, which is caused by an imbalance in energy metabolism, is associated with metabolic diseases, such as insulin resistance, type 2 diabetes, fatty liver diseases, atherosclerosis and hypertension. As known, obesity is characterized in chronic low-grade inflammation. In obesity, the microenvironment of immune cells became inflammatory by the unique activation phenotypes of immune cells such as macrophage, natural killer cell, T cell. Also, the immune cells interact each other in cellular or cytokine mechanisms, which intensify the obesity-induced inflammatory response. This phenomenon suggests the possibility of regulating the activation of immune cells as a pharmacological therapeutic strategy for obesity in addition to the common pharmacological treatment of obesity which is aimed at inhibiting enzymes such as pancreatic lipase and α-amylase or inhibiting differentiation of preadipocytes. In this review, we summarize the activation phenotypes of macrophage, natural killer cell and T cell, and their aspects in obesity. We also summarize the pharmacological substances that alleviates obesity by regulating the activation of immune cells.