• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.155-158
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• 2007

Printed organic thin-film transistor(OTFT) to use as a switching device for an organic light emitting diode(OLED) were fabricated in the microcontact printing and direct printing processes at room temperature. The gate electrodes($5{\mu}m$, $10{\mu}m$, and $20{\mu}m$) of OTFT was fabricated using microcontact printing process, and source/drain electrodes ($W/L=500{\mu}m/5{\mu}m$, $500{\mu}m/10{\mu}m$, and $500{\mu}m/20{\mu}m$) was fabricated using direct printing process with hard poly(dimethylsiloxane)(h-PDMS) stamp. Printed OTFT with dielectric layer was formed using special coating system and organic semiconductor layer was ink-jet printing process. Microcontact printing and direct printing processes using h-PDMS stamp made it possible to fabricate printed OTFT with channel lengths down to $5{\mu}m$, and reduced the process by 20 steps compared with photolithography. As results of measuring he transfer characteristics and output characteristics of OTFT fabricated with the printing process, the field effect characteristic was verified.

• 한국재료학회지
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• 제29권5호
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• pp.297-303
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• 2019

A triple-layered $PMMA/Ni_{64}Zr_{36}/PDMS$ hydrogen gas sensor using hydrogen permeable alloy and flexible polymer layers is fabricated through spin coating and DC-magnetron sputtering. PDMS(polydimethylsiloxane) is used as a flexible substrate and PMMA(polymethylmethacrylate) thin film is deposited onto the $Ni_{64}Zr_{36}$ alloy layer to give a high hydrogen-selectivity to the sensor. The measured hydrogen sensing ability and response time of the fabricated sensor at high hydrogen concentration of 99.9 % show a 20 % change in electrical resistance, which is superior to conventional Pd-based hydrogen sensors, which are difficult to use in high hydrogen concentration environments. At a hydrogen concentration of 5 %, the resistance of electricity is about 1.4 %, which is an electrical resistance similar to that of the $Pd_{77}Ag_{23}$ sensor. Despite using low cost $Ni_{64}Zr_{36}$ alloy as the main sensing element, performance similar to that of existing Pd sensors is obtained in a highly concentrated hydrogen atmosphere. By improving the sensitivity of the hydrogen detection through optimization including of the thickness of each layer and the composition of Ni-Zr alloy thin film, the proposed Ni-Zr-based hydrogen sensor can replace Pd-based hydrogen sensors.

• 한국가시화정보학회지
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• 제18권3호
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• pp.61-68
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• 2020

Thermographic phosphor (TP) thermometry is a noncontact optical measurement method and has been applied in many fields such as combustion and heat transfer. However, due to the limitation of bonding technology and measurement method, most TP thermometry studies were conducted only on the air environment with water-soluble binders. In this paper, a temperature measurement technology in water using TP is proposed by coatings of manganese activated magnesium fluorogermanate (Mg4FGeO6:Mn4+, MFG) with Polydimethylsiloxane (PDMS). Four MFG-PDMS coatings with different thicknesses were prepared. The lifetime of MFG was not affected by the thickness of the coating as a result of the experiment and analysis of phosphor intensity using a photomultiplier tube. To measure the surface temperature field of an immerged body in water, a cylinder-type cartridge heater was coated with MFG doped PDMS. Transient surface temperature field was successfully measured even the initial temperature is higher than the boiling point of water.

• Corrosion Science and Technology
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• 제8권6호
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• pp.223-226
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• 2009

Polymer coatings are commonly applied to metal substrates to prevent corrosion in aggressive environments such as high humidity and under salt water. Once the polymer coating has been breached, for example due to cracking or scratches, it loses its effectiveness, and corrosion can rapidly propagate across the substrate. The self-healing system we will describe prevents corrosion by healing the damage through a healing reaction triggered by the actual damage event. This self-healing coating solution can be easily applied to most substrate materials, and our dual-capsule healing system provides a general approach to be compatible with most common polymer matrices. Specifically, we expect an excellent anti-corrosion property of the self-healing coatings in damaged parts coated on galvanized metal substrates.

• 폴리머
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• 제30권3호
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• pp.247-252
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• 2006

환자가 요도용 카테타를 장기간 착용할 경우 세균흡착에 의한 감염이 유발되어 심각한 부작용을 경험하게 된다. 본 연구에서는 다양한 양친성 폴리우레탄을 합성하여 요도용 카테타 도포용 소재로서의 응용가능성을 확인하고자 하였다. 양친성 폴리우레탄은 친수성 고분자인 poly(ethylene oxide)(PEO)와 소수성 고분자인 poly (tetramethylene oxide) (PTMO) 또는 poly (dimethyl siloxane) (PDMS)을 연질부로 도입하여 합성하였다. 상용 실리콘 카테타에 양친성 고분자를 도포한 결과 표면의 친수성이 현저히 개선되었다. 특히, PEO의 함량이 많은 폴리우레탄일수록 친수성이 높게 나타났으며, 세균 흡착량이 감소함을 확인할 수 있었다. 결론적으로, 본 연구에서 합성한 양친성 고분자는 요도용 카테타의 도포용 소재로 적합한 것을 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.583-585
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• 2000

This study reports the fluidic handling method using hydrophobic patterns inside PDMS microchannels. In order to obtain hydrophobic patterns, we pattern fluorcarbon(FC) film surfaces by lift-off process. FC films are deposited by spin coating method and plasma polymerization method. Hydrophobic surfaces are used as the barriers to control fluid flow. Injected liquid is spontaneously filled up inside PDMS-microchannels by the capillary action. Liquid flow stops when it meets hydrophobic regions which can be the barrier against fluid flow. Then, again, when liquid is pressurized externally, liquid can move toward another hydrophilic region by external air pressure. Contact angle analyses are performed on fluorocarbon films to estimate the wettability of film surfaces.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.69-72
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• 2003

Volatile organic compounds (VOC) cause air pollution problem and deterioration of atmosphere of petrochemical and fine chemical plants. Hybrid process of membrane and cold-condensation were developed and it effectively removed and recycled the VOC. Operation parameters of the process were optimized to attain hish removal and recycle of VOC. Composite membranes for organic vapor separation were developed in this work by PDMS coating and plasma polymerization on polypropylene and polysulfone support membranes. PDMS and various silicone monomers were tested for several organic vapors such as benzene, toluene, TCE, and HCFC, which are produced in petrochemical and fine chemical industry and causes air pollution problems if are released to atmosphere. Composite membranes prepared in this work showed appreciable performance in terms of organic vapor removal and reuse. Performance variation of the membranes was correlated with their surface characteristics.

• 대한전자공학회논문지SD
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• 제48권6호
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• pp.7-14
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• 2011

본 논문은 PDMS(polydimethyl siloxane) 스탬프를 이용한 원통형 마이크로 접촉인쇄(roll-type micro-contact printing)에 관한 것으로 대면적 플라스틱 기판에 미세 금속 전극 인쇄를 PDMS 스탬프의 평탄화, 은 나노 잉크의 은 함량, 공정변수인 코팅속도, 잉킹속도, 프린팅속도, 프린팅 압력을 조절하여 가장 우수한 인쇄특성을 나타내는 조건을 도출하였다. 그 결과 면적 $4.5cm\;{\times}\;4.5cm$ 기판에 최소선폭 10 um, 두께 300 nm, 표면거칠기 40 nm 이하, 비저항 $2.08\;{\times}\;10^{-5}{\Omega}{\cdot}cm$의 특성을 갖는 은미세 전극을 인쇄하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제26권5호
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• pp.20-29
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• 2022

이 연구에서는 ME 방식 3D 프린터로 출력한 시멘트 복합체의 내구성을 개선하기 위해 PDMS, 규산나트륨, 표면강화재를 침지 후 도포하는 방식으로 후처리 하였으며 각각의 내구성 개선 정도를 평가하였다. 그 결과, 모든 평가에서 후처리 한 시험체의 내구성능이 그렇지 않은 시험체에 비해 내구성이 개선되는 경향을 나타냈다. 내흡수성과 염소이온 침투 저항성, 탄산화 저항성의 경우 PDMS로 후처리 했을 때 후처리 하지 않은 시험체에 비해 각각 평균 36.3 %, 77.1 %, 50.4 % 개선되어 가장 우수한 것으로 나타났으며 내동해성의 경우 규산나트륨으로 후처리 했을 때 평균 47.5 % 개선되어 가장 우수한 것으로 나타났다. 3D 프린팅용 시멘트 복합체의 후처리 용액 중 대체로 PDMS가 우수한 것으로 나타났으나 이 연구에서 제안한 바와 같이 침지 후 도포하는 후처리 방식은 3D 프린터로 출력한 시멘트 복합체 구조물에 실질적으로 적용하기 어려울 수 있으므로 시공성을 고려한 성능개선재료에 대한 후속 연구가 필요할 것으로 판단된다.

• 한국군사과학기술학회지
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• 제18권2호
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• pp.139-145
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• 2015

In this paper, the flexible piezoelectric nanocomposite generator(NCG) device based on $BaTiO_3$ nanostructures was fabricated via simple and low-cost spin coating method. The $BaTiO_3$ nanostructures synthesized by self-assembly reaction showed dendrite morphologies. To produce the piezoelectric nanocomposite(p-NC layer) which acts as an electric energy source in NCG device, the piezoelectric nanopowders($BaTiO_3$) were dispersed in polydimethylsiloxane(PDMS). Sequently, the p-NC layer was inserted in two dielectric layer of PDMS; these layers enabled the NCG device flexibility as well as durability prohibiting detachment(exfoliation) for significantly mechanical bending motions. The fabricated NCG device shows average maximum open circuit voltage of 6.2 V and average maximum current signals of 300 nA at 20 wt% composition of $BaTiO_3$ nanostructures in p-NC layer. Finally, the flexible energy harvester generates stable output signals at any rate of frequency which were used to operate LCD device without any external energy supply.