The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Kwon-shik Park - One of the best experts on this subject based on the ideXlab platform.
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Highly bendable characteristics of amorphous indium–gallium–zinc-oxide transistors embedded in a Neutral Plane
Applied Physics Express, 2015Co-Authors: Chang Bum Park, Soon Sung Yoo, Kwon-shik ParkAbstract:The electromechanical response of an amorphous indium–gallium–zinc-oxide (a-IGZO) thin-film transistor (TFT) fabricated on a polyimide substrate was investigated as a function of the Neutral axis location and strain history of the bending system. Here, we demonstrate the pronounced bending characteristics of a-IGZO TFTs and their backPlane under extreme mechanical strain when they are embedded in a Neutral Plane (NP). After being subjected to tensile stress, the devices positioned near the NP were observed to function well against a cyclic bending stress of 2 mm radius with 100,000 times, while TFTs farther from the Neutral surface exhibited modified electrical properties.
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highly bendable characteristics of amorphous indium gallium zinc oxide transistors embedded in a Neutral Plane
Applied Physics Express, 2015Co-Authors: Chang Bum Park, Soon Sung Yoo, Kwon-shik ParkAbstract:The electromechanical response of an amorphous indium–gallium–zinc-oxide (a-IGZO) thin-film transistor (TFT) fabricated on a polyimide substrate was investigated as a function of the Neutral axis location and strain history of the bending system. Here, we demonstrate the pronounced bending characteristics of a-IGZO TFTs and their backPlane under extreme mechanical strain when they are embedded in a Neutral Plane (NP). After being subjected to tensile stress, the devices positioned near the NP were observed to function well against a cyclic bending stress of 2 mm radius with 100,000 times, while TFTs farther from the Neutral surface exhibited modified electrical properties.
R Feng - One of the best experts on this subject based on the ideXlab platform.
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a new model for determining Neutral Plane position in shaft space of a building under fire situation
Building and Environment, 2008Co-Authors: J Y Zhang, R Huo, R FengAbstract:In this study, a new model is proposed for predicting the location of the Neutral Plane inside the shaft space of a building under fire situation. The shaft space of the building is divided into two zones, i.e., fire zone and inner space, in the model. The temperature is assumed uniform in each zone. To validate the proposed model, a parametric numerical study is also carried out by using a computational fluid dynamics (CFD) code, i.e., FDS code. The comparisons between the proposed model and the CFD model are processed and the agreements between the two approaches are satisfied. It is found that the location of the Neutral Plane is above the mid-height of the building and the simulation results are consistent with the proposed model approximately. The ratio of the Neutral Plane height to ceiling height depends on the ventilation condition of the fire room greatly, which is found varying between 0.50 and 0.62.
Seung Min Han - One of the best experts on this subject based on the ideXlab platform.
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Neutral Plane control by using polymer graphene flake composites for flexible displays
RSC Advances, 2017Co-Authors: Byungil Hwang, Sung-jin Lim, Minkyu Park, Seung Min HanAbstract:Controlling the Neutral Plane of a multilayer structure is crucial in designing a reliable flexible display, where the bending strain imposed on the individual layers that are positioned closer to the Neutral Plane can be significantly reduced. In this study, we explore the usage of polymer/graphene composites with different concentrations of graphene flakes to systematically vary the modulus in attempt to control the location of the Neutral Plane to the desirable position. Nanoindentation of the PMMA/graphene composite film on Si substrate revealed that increasing the graphene flake content led to the enhancement in hardness and modulus of the composite. The increased Young's modulus caused a shift in the Neutral Plane position towards the organic emissive layers by ∼2.2 μm that resulted in a reduction of bending strain in the organic light emitting diodes with a typical multilayer structure. Furthermore, gas permeability against O2 and water molecules showed that the gas transmission rate of PMMA/graphene composites decreased as the content of graphene flakes increased since the randomly mixed graphene in PMMA can efficiently hinder the O2 and water molecules from transporting through the thickness of the composite, thereby enhancing the barrier properties.
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Neutral Plane control by using polymer/graphene flake composites for flexible displays
RSC Advances, 2017Co-Authors: Byungil Hwang, Sung-jin Lim, Minkyu Park, Seung Min HanAbstract:Controlling the Neutral Plane of a multilayer structure is crucial in designing a reliable flexible display, where the bending strain imposed on the individual layers that are positioned closer to the Neutral Plane can be significantly reduced. In this study, we explore the usage of polymer/graphene composites with different concentrations of graphene flakes to systematically vary the modulus in attempt to control the location of the Neutral Plane to the desirable position. Nanoindentation of the PMMA/graphene composite film on Si substrate revealed that increasing the graphene flake content led to the enhancement in hardness and modulus of the composite. The increased Young's modulus caused a shift in the Neutral Plane position towards the organic emissive layers by ∼2.2 μm that resulted in a reduction of bending strain in the organic light emitting diodes with a typical multilayer structure. Furthermore, gas permeability against O2 and water molecules showed that the gas transmission rate of PMMA/graphene composites decreased as the content of graphene flakes increased since the randomly mixed graphene in PMMA can efficiently hinder the O2 and water molecules from transporting through the thickness of the composite, thereby enhancing the barrier properties.
Chang Bum Park - One of the best experts on this subject based on the ideXlab platform.
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Highly bendable characteristics of amorphous indium–gallium–zinc-oxide transistors embedded in a Neutral Plane
Applied Physics Express, 2015Co-Authors: Chang Bum Park, Soon Sung Yoo, Kwon-shik ParkAbstract:The electromechanical response of an amorphous indium–gallium–zinc-oxide (a-IGZO) thin-film transistor (TFT) fabricated on a polyimide substrate was investigated as a function of the Neutral axis location and strain history of the bending system. Here, we demonstrate the pronounced bending characteristics of a-IGZO TFTs and their backPlane under extreme mechanical strain when they are embedded in a Neutral Plane (NP). After being subjected to tensile stress, the devices positioned near the NP were observed to function well against a cyclic bending stress of 2 mm radius with 100,000 times, while TFTs farther from the Neutral surface exhibited modified electrical properties.
-
highly bendable characteristics of amorphous indium gallium zinc oxide transistors embedded in a Neutral Plane
Applied Physics Express, 2015Co-Authors: Chang Bum Park, Soon Sung Yoo, Kwon-shik ParkAbstract:The electromechanical response of an amorphous indium–gallium–zinc-oxide (a-IGZO) thin-film transistor (TFT) fabricated on a polyimide substrate was investigated as a function of the Neutral axis location and strain history of the bending system. Here, we demonstrate the pronounced bending characteristics of a-IGZO TFTs and their backPlane under extreme mechanical strain when they are embedded in a Neutral Plane (NP). After being subjected to tensile stress, the devices positioned near the NP were observed to function well against a cyclic bending stress of 2 mm radius with 100,000 times, while TFTs farther from the Neutral surface exhibited modified electrical properties.
J Y Zhang - One of the best experts on this subject based on the ideXlab platform.
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a new model for determining Neutral Plane position in shaft space of a building under fire situation
Building and Environment, 2008Co-Authors: J Y Zhang, R Huo, R FengAbstract:In this study, a new model is proposed for predicting the location of the Neutral Plane inside the shaft space of a building under fire situation. The shaft space of the building is divided into two zones, i.e., fire zone and inner space, in the model. The temperature is assumed uniform in each zone. To validate the proposed model, a parametric numerical study is also carried out by using a computational fluid dynamics (CFD) code, i.e., FDS code. The comparisons between the proposed model and the CFD model are processed and the agreements between the two approaches are satisfied. It is found that the location of the Neutral Plane is above the mid-height of the building and the simulation results are consistent with the proposed model approximately. The ratio of the Neutral Plane height to ceiling height depends on the ventilation condition of the fire room greatly, which is found varying between 0.50 and 0.62.
