• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.319-319
• /
• 2010

Dye-sensitized solar cells (DSSCs) based on plastic substrates have attracted much attention mainly due to extensive applications such as ubiquitous powers, as well as the practical reasons such as light weight, flexibility and roll-to-roll process. However, conventional high temperature fabrication technology for glass based DSSCs, cannot be applied to flexible devices because polymer substrates cannot withstand the heat more than $150^{\circ}C$. Therefore, low temperature fabrication process, without using a polymer binder or thermal sintering, was required to fabricate necked $TiO_2$. In this presentation, we proposed polymer-inorganic composite photoelectrode, which can be fabricated at low temperature. The concept of composite electrode takes an advantage of utilizing elastic properties of polymers, such as good impact strength. As an elastic material, poly(methyl methacrylate) (PMMA) is selected because of its optical transparency and good adhesive properties. In this work, a polymer-inorganic composite electrode was constructed on FTO/glass substrate under low temperature sintering condition, from the mixture of PMMA and $TiO_2$ colloidal solution. The effect of PMMA composition on the photovoltaic property was investigated. Then, the enhanced mechanical stability of this composite electrode on ITO/PEN substrate was also demonstrated from bending test.

• Molecules and Cells
• /
• v.42 no.10
• /
• pp.729-738
• /
• 2019

Autophagy is an important process for protein recycling. Oligomerization of p62/SQSTM1 is an essential step in this process and is achieved in two steps. Phox and Bem1p (PB1) domains can oligomerize through both basic and acidic surfaces in each molecule. The ZZ-type zinc finger (ZZ) domain binds to target proteins and promotes higher-oligomerization of p62. This mechanism is an important step in routing target proteins to the autophagosome. Here, we determined the crystal structure of the PB1 homo-dimer and modeled the p62 PB1 oligomers. These oligomer models were represented by a cylindrical helix and were compared with the previously determined electron microscopic map of a PB1 oligomer. To accurately compare, we mathematically calculated the lead length and radius of the helical oligomers. Our PB1 oligomer model fits the electron microscopy map and is both bendable and stretchable as a flexible helical filament.

• Computers and Concrete
• /
• v.33 no.4
• /
• pp.385-398
• /
• 2024

As concrete dominates the construction industry, alternatives to traditionally used steel reinforcement are being sought. This study explored the suitability of carbon fiber-reinforced polymer (CFRP) as a substitute within rigid frames, focusing on its impact on section ductility and overall structural durability against seismic events. However, current design guidelines address quasi-static loads, leaving a gap for dynamic or extreme circumstances. Our approach included multiscale simulations, parametric study, and energy dissipation analyses, drawing upon a unique adaptation of modified compression field theory. In our efforts to optimize macro and microparameters to improve yield strength, manage brittleness, and govern failure modes, we also recognized the potential of CFRP's high corrosion resistance. This characteristic of CFRP could significantly reduce the frequency of required repairs, thereby contributing to enhanced durability of the structures. The research reveals that CFRP's durability and seismic resistance are attributed to plastic joints within compressed fibers. Notably, CFRP can impart ductility to structural designs, effectively balancing its inherent brittleness, particularly when integrated with quasi-brittle materials. This research challenges the notion that designing bendable components with carbon fiber reinforcement is impractical. It shows that creating ductile bending components with CFRP in concrete is feasible despite the material's brittleness. This funding overturns conventional assumptions and opens new avenues for using CFRP in structural applications where ductility and resilience are crucial.

• Journal of Fashion Business
• /
• v.24 no.5
• /
• pp.140-157
• /
• 2020

The purpose of this study is to develop three functions for smartphones and PCs using a textile touch sensor in an everyday sports jacket and to present their usefulness; to this end, we have developed a mutual capacitive textile touch sensor and corresponding structure, and we have implemented three functions into a textile touch sensor jacket, of which we also conducted a usability evaluation. The jacket has a sensor on the wrist of the left sleeve and a device on the left arm. The sensor system can be divided into three main categories: a sensor acting as a switch, a circuit connecting the sensor and the device, and the device that acts as power control and system on/off. The functions are implemented in the texture touch sensor jacket in three modes: cell phone mode, music mode, and PPT presentation mode. We conducted an evaluation of each function in each mode, which indicated that all functions performed well without errors and that the switch had excellent operation for the number and intensity of touch. In terms of usability in a humid environment, the performance of touch functions was found to be equally implemented. In the temperature environment, neither high nor low temperatures caused issues with the functions. A wearing satisfaction assessment evaluated psychological satisfaction, clothing convenience, device convenience, device usability, and device effectiveness. This research jacket is thought to be desirable for the relatively bendable, flexible, and intimate sensor used on the clothing, and the circuit made of conductive fabric tape.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.31 no.5
• /
• pp.330-334
• /
• 2018

With the development of the Internet of Things, the use of flexible displays has become widespread. In particular, the use of curved, bendable, and rollable displays is increasing. Flexible display production processes include various important components such as lamination material, flexible substrates, and adhesives. Among them, improvement of the lamination process comprises a large proportion of efforts for further development. In this paper, we attempt to improve the transmittance of the display substrate by performing a bubble removal process after adhesion. The transmittance of the glass substrate with the bubble removal process was 5~12% higher than that of the substrate without the bubble removal process. The fill-strength after the bubble removal process was improved by 21.4%, and the shear-strength was improved by 43.9%.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.1
• /
• pp.63-71
• /
• 2020

Recently, to improve convenience, flexible electronics are quickly being developed for a number of application areas. Flexible electronic devices comprise characters such as being bendable, stretchable, foldable, and wearable. Effectively manufacturing flexible electronic devices requires high efficiency, low costs, and simple processes for manufacturing technology. Through this study, we enabled the rapid production of multifunctional flexible bending sensors using a simple, low-cost Fused Deposition Modeling (FDM) 3D printer. Furthermore, we demonstrated the possibility of the rapid production of a range of functional flexible bending sensors using a simple, low-cost FDM 3D printer. Accurate and reproducible functional materials made by FDM 3D printers are an effective tool for the fabrication of flexible sensor electronic devices. The 3D-printed flexible bending sensor consisted of polyurethane and a conductive filament. Two patterns of electrodes (straight and Hilbert curve) for the 3D printing flexible sensor were fabricated and analyzed for the characteristics of bending displacement. The experimental results showed that the straight curve electrode sensor sensing ability was superior to the Hilbert curve electrode sensor, and the electrical conductivity of the Hilbert curve electrode sensor is better than the straight curve electrode sensor. The results of this study will be very useful for the fabrication of various 3D-printed flexible sensor devices with multiple degrees of freedom that are not limited by size and shape.

• Journal of Convergence for Information Technology
• /
• v.9 no.3
• /
• pp.75-81
• /
• 2019

In this work, we investigated a low temperature polycrystalline silicon (LTPS) thin film transistors fabrication process on polymer layers. Dehydrogenation and activation processes were performed by a furnace annealing at a temperature of $430^{\circ}C$ for 2 hr. The crystallization of amorphous silicon films was formed by excimer laser annealing (ELA) method. The p-type device performance, fabricated by polycrystalline silicon (poly-Si) films, shows a very good performance with field effect mobility of $77cm^2/V{\cdot}s$ and on/off ratio current ratio > $10^7$. We believe that the poly-Si formed by a LTPS process may be well suited for fabrication of poly-Si TFTs for bendable panel displays such as AMOLED that require circuit integration.

• Journal of Convergence for Information Technology
• /
• v.11 no.3
• /
• pp.167-173
• /
• 2021

There is an increasing interest in manufacturing various electronic devices on a bendable substrate. In this paper, we observed a surface morphology by annealing for 20 minutes at temperatures of 150 ℃, 350 ℃, and 550 ℃, respectively, with samples coated by chromium and aluminum. Data on surfaces are investigated using high-resolution SEM and AFM that can measure roughness up to nm. There is no difference from the sample without heat treatment up to 350 ℃, but the change of crystal grains can be observed at 550 ℃. In the future, for application to the flexible optoelectronic field, additional characteristics such as electrical conductivity and reflectivity will be analyzed and optical devices will be manufactured. In conclusion, we will explore the possibility of applying metal materials to flexible electronic devices.

• Journal of Convergence for Information Technology
• /
• v.10 no.9
• /
• pp.28-34
• /
• 2020

In this paper, an optical sensor based on an AZO semiconductor material is fabricated on an OHP film with high transmittance, and the characteristics of the optical element and the properties of the semiconductor material are described. In order to realize a flexible optical device, which is a major issue in the field of near-electronic devices, a transparent and bendable OHP film was used as a substrate. In addition, ITO, which is used for mass production as a transparent electrode and a semiconductor material, is expensive due to the scarcity of indium. Therefore, it is necessary to find a material that can replace it. The optical and electrical properties of the Au/Al/AZO/OHP structure are implemented to evaluate whether AZO is possible. It was found that devices and materials had no characteristic change by bending, and these results provide a possibility for application to a next-generation device. However, it is necessary to remove fine scratches on the surface of the OHP film, as well as optimized devices based on materials and structures that can improve the photocurrent.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.489-492
• /
• 2005

We report new polymer stabilized ferroelectric liquid crystal (PSFLC) cells with mechanical stability which is achievable by introducing photospacers in the cells. It was found that the mechanical st ability of the PSFLC cell was effected by introduction of photo spacers. We analyzed the dependence of mechanical stability and memory property on the density of photospacers in the PSFLC cell. The stability and memory properties of PSFLC Cells depending on photospacer density are discussed. 1. Introduction Recently, flexible displays have attracted much attention because they have remarkable advantages: thinner, lighter, non-breakable and conformable features. Flexible displays have various potential applications such as e-book and e-paper displays utilizing the distinct features. E-book and E-paper displays demand very low power consumption, so that bistable memory liquid crystal modes are required in case of flexible plastic LCDs for those application. Three kinds of memory LC modes have been developed; bistable nematic, bistable cholesteric and bistable FLC. Among them SSFLC as one of bistable FLC has big advantages such as low driving voltage, wide view angle and fast response time, SSFLC cells are, however, very weak against mechanical shock. Polymer stabilized FLC (PSFLC) has been developed to overcome the poor mechanical stability of SSFLC. PSFLC was known to have network structure that FLCs are oriented with smectic layer ordering in polymer network. The polymer network stabilizes the FLC orientation, which leads to improvement of mechanical stability of PSFLCD. A lot of studies have been done for the application of PSFLC to flexible $LCDs.^{[1{\sim}12]}$ However, it should be noted that PSFLC does not have sufficient mechanical stability for the particular applications such as smart card LCD, where LCD is highly bendable.Bead spacer was mainly used to maintain cell gap of conventional PSFLCDs. But the spacer density of it is not locally uniform in the cell, so that it is generally difficult that the PSFLCDs with bead spacers show sufficient mechanical stability. In order to more improve the mechanical stability of PSFLCDs, we introduced photospacers into PSFLCDs. In this paper, we describe the improvement of mechanical stability by introducing photospacers into PSFLCDs.