• 한국전기전자재료학회논문지
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• 제37권3호
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• pp.241-252
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• 2024

With the recent development of emerging technologies, information acquisition and delivery between users has been actively conducted, and inorganic thin film transfer technology that effectively transfers various materials and devices is being studied to develop flexible electronic devices accordingly. This is aimed at innovative structural changes and functional improvement of electronic devices in the era of the Internet of Things (IoT). In particular, advanced technologies such as microLEDs are used to realize high-resolution flexible displays, and the possibility of heterogeneous integrated technologies can be presented by precisely transferring materials to substrates through various transfer process. This paper introduced physical, chemical, and self-assembly transfer methods based on inorganic thin film materials to implement heterogeneous integrated flexible semiconductor systems and introduces the results of application studies of semiconductor devices obtained through different transfer technologies. These studies are expected to bring about innovative changes in the field of smart devices, medical technology, and user interfaces in the future.

• 한국기계가공학회지
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• 제19권1호
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• pp.81-88
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• 2020

In this paper, the performances of the electrical characteristics of the Fused Deposition Modeling (FDM) 3D-printed flexible resistance sensor was evaluated. The FDM 3D printing flexible resistive sensor is composed of flexible-material thermoplastic polyurethane and a conductive PLA (carbon black conductive polylactic acid) polymer. While 3D printing, polymer filaments heat up quickly before being extruded and cooled down quickly. Polymers have poor thermal conductivity so the heating and cooling causes unevenness, which then results in internal stress on the printed parts due to the rapidity of the heating and cooling. Electrical resistance measurements show that the 3D-printed flexible sensor is unstable due to internal stress, so the 3D-printed flexible sensor resistance curve does not match the increases and decreases in the displacement curve. Therefore, annealing was performed to eliminate the mismatch between electrical resistance and displacement. Annealing eliminates residual stress on the sensor, so the electrical resistance of the sensor increases and decreases in proportion to displacement. Additionally, the resistance is lowered in comparison to before annealing. The results of this study will be very useful for the fabrication of various devices that employ 3D-printed flexible sensor that have multiple degrees of freedom and are not limited by size and shape.

• 한국화재소방학회논문지
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• 제16권4호
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• pp.77-84
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• 2002

본 연구는 플라스틱재료 중 비드발포폴리스티렌폼, 압출발포폴리스티렌폼, 연질폴리우레탄폼, 경질폴리우레탄폼, 경질PVC파이프, 비닐장판, 폴리에틸렌폰(비난연), 폴리에틸렌폼(난연)를 대상으로 연소가스 독성평가를 위하여 NES 713 방법에 따라 발생되는 연소가스를 가스텍(GASTEC) 가스검지관을 이용하여 조사하였다. 연구결과 플라스틱재료의 연소시 발생되는 연소가스에 인간이 30분 동안 노출될 경우 사망에 이르는 독성지수 1 이상을 갖고 있었으며, 각 실험체의 독성지수 결과는 4.3∼179.2로 나타났으며 경질 PVC파이프가 179.2로 가장 높았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.411-412
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• 2007

EL (electro luminescent) is generally studied as a large size plane light emitting device and flexible light source because of it's simple manufacturing process. In this experiment, we manufactured flexible white emitting light source using Ni-foil with blue phosphor and color change materials. With increasing the thickness of color change material, the luminance of white emission is increased and the color coordinate of white color was shifted to pure white of (0.317,0.328) by strong emission of color change materials excited by blue excitation spectra. Also the luminance level was 30% higher in white emitting light device than blue only light source.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.473-476
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• 2003

This paper shows necessity of encapsulation layer to maximite flexibility of brittle indium-tin-oxide (ITO) on polymer substrates. And, Young's modulus (E) of encapsulation layer have an significant effect on external bending stress and the coefficient of thermal expansion (CTE) of that have a significant effect on internal thermal stress. To compare magnitude of total mechanical stress including both bending stress and thermal stress, the mechanical stress of triple-layer structure (substrate / ITO / encapsulation layer or substrate / buffer layer / ITO) can be quantified and numerically analyzed through the farthest cracked island position. As a result, it should be noted that multi-layer structures with more elastic encapsulation material have small mechanical stress compared to that of buffer and encapsulation structure of large Young's modulus material when they were externally bent.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1249-1250
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• 2004

In this paper, we report new technique of preparation of material for flexible displays and E-paper technology. This material represents porous polymeric fiber based on polyacrylonitrile filled by liquid crystal.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.129-129
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• 2003

전기변색(electrochromism)은 전기화학적 산화, 환원 과정을 통해 가역적인 광학특성의 변화를 갖는 현상을 말하며, 이를 이용한 전기변색소자(electrochromic device)는 전력 소모가 적고 변색효율이 크다는 장점으로 인해 smart window, display, mirror 등에 응용될 수 있다. 전기변색소자는 구조상 투명 기판, 투명 전도체, 환원 착색 물질 (cathodic coloration material), 산화 착색 물질(anodic coloration material), 그리고 투명 이온 전도체로 구성된다. 일반적으로 투명 기판으로는 열적 안정성이 좋은 유리기판을 사용하여 window에 응용할 수 있는 장점이 있는 반면 다양한 형태를 갖는 소자를 제작하기에는 그 한계가 있다.

• 산업공학
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• 제7권2호
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• pp.145-155
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• 1994

In this paper, we analyzed weak points of press process with the rolled thin flexible plate. The problems which are caused by the adhesion of blank on the surface of die and the separation of blank from scrap during its transportation after blanking were solved by the redesign of the structure of die and the development of special equipment for material handling. It is our purpose to make better the automation of blanking process and the safety for worker by the improvement of flexible material handling.

• 한국전기전자재료학회논문지
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• 제37권2호
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• pp.195-201
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• 2024

The low-temperature deposition of BaNi_(2-x)Co_xFe₁₆O₂₇ thin films with a Ba hexaferrite structure for electromagnetic shielding was studied. The BaNi_(2-x)Co_xFe₁₆O₂₇ thin films produced through the spin spray process were suitable for thin film deposition on a flexible substrate because it crystallized well at low temperature below 90℃. The change in shielding characteristics depending on the Co content of the BaNi_(2-x)Co_xFe₁₆O₂₇ thin film was investigated, and excellent shielding characteristics with S21 of -1 dB were obtained in a wide frequency range of 26~40 GHz when the Co content was 0.4 or more. The purpose of this study is to analyze changes in shielding properties caused by change in Co content in relation to phase changes in BaNi_(2-x)Co_xFe₁₆O₂₇ and obtain basic data for developing excellent flexible electromagnetic wave shielding materials.

• Korean Chemical Engineering Research
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• 제57권3호
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• pp.351-357
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• 2019

2018년 울산에서 Flexible hose의 파단으로 발생한 염소 누출사고를 분석하여 국내 설계 및 관리 기준을 제시하기 위한 연구를 수행하였다. 누출 사고가 발생한데는 다양한 원인이 있지만, 본 논문에서는 직접적 원인인 Flexible hose의 파단을 분석하는데 초점을 맞추었다. 분석 결과, 사고가 발생한 사업장에서 염소 이송에 사용하는 Flexible hose 는 재질 및 사용 두께 측면에서 부적절 했고, 사용 전 압력 테스트도 운전압력 이하에서 하는 등 문제가 있었다. 설문조사를 통하여 염소를 취급하는 울산지역의 다섯 곳의 사업장을 확인한 결과, 한 곳을 제외하고 염소 이송에 부적절한 Flexible hose를 사용하고 있었다. 현재 염소 이송용 Flexible hose의 설계에 대한 국내 기준이 없어 사용하는 Flexible hose의 적정성을 검토하는데 어려움이 있다. 본 연구를 통하여 국내에 적용할 수 있는 염소 이송용 Flexible hose의 설계 기준을 제시하였다. 본 논문에서 제시한 기준을 설계 및 검토에 적용한다면 염소 이송 시 발생할 수 있는 Flexible hose 파단의 위험성을 경감시키는데 기여할 것이다.