• 통합자연과학논문집
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• 제17권2호
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• pp.53-58
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• 2024

This study explores the enhancement of mechanical properties in Polymethyl Methacrylate (PMMA) composites through the incorporation of Methyl Methacrylate (MMA) and Ethylene Glycol Dimethacrylate (EGDMA). Utilizing Digital Light Processing (DLP) technology, we conducted a series of experiments to analyze the impact of varying concentrations of MMA and EGDMA on PMMA. The results indicate that while MMA demonstrates non-linear and variable mechanical strength across different PMMA concentrations, EGDMA consistently improves mechanical strength as PMMA concentration increases. This consistent enhancement by EGDMA suggests a stable and predictable reinforcement effect, which is critical for applications requiring high mechanical strength. Our comparative analysis highlights that EGDMA is a more effective additive than MMA for optimizing the mechanical performance of PMMA composites. Specifically, EGDMA's ability to provide uniform reinforcement across various PMMA concentrations makes it ideal for high-strength applications. These findings are significant for material scientists and engineers focused on the design and development of advanced PMMA-based materials. In conclusion, this research underscores the importance of selecting appropriate additives to enhance the mechanical properties of PMMA composites. The superior performance of EGDMA in reinforcing PMMA suggests its potential for broader applications in fields such as automotive, construction, medical devices, and 3D printing. This study provides valuable insights that can guide future research and development in high-performance composite materials, paving the way for innovative applications and improved material efficiency.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.107-108
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• 2012

• 기계와재료
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• 제19권4호통권74호
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• pp.117-130
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• 2008

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.14.1-14.1
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• 2009

We found a high yield synthetic route to organic-soluble metal nanoparticles in the concentrated organic phase. The organic phase contains metal salt, amines, fatty acids, nonpolar solvent, and reducing agent. Even using only generic chemicals, organic-soluble silver and copper nanoparticles could be easily obtained by this simple and rapid reaction scheme at large scale. The hydrocarbon-protected metal nanoparticles showed excellent dispersion properties and were successfully printed onto polymer substrates. The printed pattern was heated at $200^{\circ}C$, which showed very low specific electrical resistance (< 10 uOhm$\cdot$cm), sufficient for conducting line of various printable devices.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.3.2-3.2
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• 2009

Development of printed electronics, which is occasionally referred to as 'flexible' or 'polymer' electronics, has attracted considerable world wide attention in recent years. Printed (or flexible) electronics is currently expected to represent a new form of electronics and open up wide ranging applications in displays, electron devices for medical use, sensors, and other areas. This presentation aims to provide a strategy for scalable and viable paths to accomplish flexible, printable, large area circuits displaying high performance. Novel approaches evolving from system on package (SoP) to system on flex (SoF) technology will allow the integration of heterogeneous materials platforms into a system which is needed to enhance the functionality of the system. The talk also includes speculations about areas on which future advances in printed electronics could have a substantial impact along with a brief introduction of the Korea Printed Electronics Association (KoPEA).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.168.1-168.1
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• 2014

We developed poly (3,4-ethylene dioxylene thiophene):poly (styrene sulfonic acid) (PEDOT:PSS)-free organic solar cells (OSCs) using buffer and anode combined Ta doped $In_2O_3$ (ITaO) electrodes. To optimize the ITaO electrodes, we investigated the effect of $Ta_2O_5$ doping power on the electrical, optical, and structural properties of the co-sputtered ITaO films. The optimized ITaO film doped with 20 W $Ta_2O_5$ radio frequency power showed sheet resistance of 17.11 Ohm/square, a transmittance of 93.45%, and a work function of 4.9 eV, all of which are comparable to the value of conventional ITO electrodes. The conventional bulk heterojunction OSC with ITaO anode showed a power conversion efficiency (PCE) of 3.348% similar to the OSCs (3.541%) with an ITO anode. In addition, OSCs fabricated on an ITaO electrode successfully operated without an acidic PEDOT:PSS buffer layer and showed a PCE of 2.634%, which was much higher than the comparable no buffer OSC with an ITO anode. Therefore, co-sputtered ITaO electrodes simultaneously acting as a buffer and an anode layer can be considered promising transparent electrodes for cost-efficient and reliable OSCs because they can eliminate the use of an acidic PEDOT:PSS buffer layer.

• 마이크로전자및패키징학회지
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• 제22권1호
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• pp.7-14
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• 2015

Recently, advances in nano-material researches have opened the door for various transparent conductive materials, which include carbon nanotube, graphene, Ag and Cu nanowire, and printable metal grids. Among them, Ag nanowires are particularly interesting to synthesize because bulk Ag exhibits the highest electrical conductivity among all metals. Here we reviewed recently-published research works introducing various devices from organic light emitting diode to tactile sensing devices, all of which are employing AgNW for a conducting material. They proposed methods to enhance the stretchability and reversibility of the transparent electrodes, and apply them to make various flexible and stretchable electronics. It is expected that Ag nanowires are applicable to a wide range of high-performance, low-cost, stretchable electronic devices.

• Current Optics and Photonics
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• 제3권1호
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• pp.66-71
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• 2019

Application of liquid crystal (LC) materials to a flexible device is challenging because the bending of LC displays easily causes change in thickness of the LC layer and orientation of LCs, resulting in deterioration in a displayed image quality. In this work, we demonstrate a prototype device combining a flexible polymer substrate and an optically isotropic LC-polymer composite in which the device consists of interdigitated in-plane switching electrodes deposited on a flexible colorless polyimide substrate and the composite consisting of nano-sized LC droplets in a polymer matrix. The device can keep good electro-optic characteristics even when it is in a bending state because the LC orientation is not disturbed in both voltage-off and -on states. The proposed device shows a high potential to be applicable for future flexible LC devices.

• 마이크로전자및패키징학회지
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• 제30권3호
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• pp.56-63
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• 2023

본 연구에서는 졸-겔 IGZO(Indium-Gallium-Zinc Oxide) 박막을 만들고 이에 전자빔을 조사 한 후 박막 트랜지스터로 제작하여 전자빔 조사가 박막 트랜지스터의 전기적 특성에 미치는 영향을 비교 분석하였다. 특히 전자빔이 조사되는 환경을 대기 중과 질소 분위기(<200 ppm O₂)로 두고 전자빔 조사 선량 세기를 100kGy와 200kGy로 각각 조사한 후 350℃ 온도에서의 열처리만 진행한 비교군과 비교 분석을 진행하였다. 전자빔 조사에 따른 졸-겔 IGZO 박막의 물성 변화를 분석하기 위해 UV-Visible spectroscopy, X-ray diffraction(XRD)와 X-ray photoelectron spectroscopy(XPS)를 분석 결과, 전자빔 조사 전·후의 모든 조건 하에서 가시광 영역에서의 80% 이상의 높은 투과도를 보여줌을 확인할 수 있었고, XRD 분석 결과를 통해 전자빔 조사와 관계없이 비정질 특성을 유지함을 확인하였다. 특히 전자빔 조사에 따라 졸-겔 IGZO 박막에 화학적 조성 변화가 있음을 확인하였는데, 질소 분위기에서 전자빔을 조사하게 되면 M-O결합과 관련된 peak이 차지하는 비율이 높아짐을 확인할 수 있었다. 질소 분위기에서 전자빔이 조사된 TFT들은 on/off 비율, 전자 이동도에서 향상된 특성을 보여주었으며, 시간에 따라 트랜지스터의 특성들(on/off 비율, 문턱전압, 전자이동도, 하위임계값 스윙)의 수치 또한 큰 변화 없이 유지됨이 확인되어, 졸-겔 공정 TFT 제작에 있어서 질소 분위기에서의 전자빔 조사공정이 IGZO기반 박막 트랜지스터의 전기적특성의 개선에 기여할 수 있을 것으로 기대된다.

• Journal of Welding and Joining
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• 제32권3호
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• pp.34-42
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• 2014

Flexible devices have been developed from their rigid, heavy origins to become bendable, stretchable and portable. Such a paper displays, e-skin, textile electronics are emerging research areas and became a mainstream of overall industry. Thin film transistors, diodes and sensors built on plastic sheets, textile and other unconventional substrates have a potential applications in wearable displays, biomedical devices and electronic system. In this review, we describe current trends in technologies for flexible/wearable electronics.