• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.218-222
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• 2021

Wearable multi-sensors based on nanocrystals have attracted significant attention, and studies on patterning technology to implement such multi-sensors are underway. Conventional patterning processes may affect material properties based on high temperatures and harsh chemical conditions. In this study, we developed an inkjet printing technique that can overcome these drawbacks through the application of patterning processes at room temperature and atmospheric pressure. Nanocrystal-based ink is used to adjust properties efficiently. Additionally, the viscosity and surface tension of the solvents are investigated and optimized to increase patterning performance. In the patterning process, the electrical, electrothermal, and electromechanical properties of the nanocrystal pattern are controlled by the ligand exchange process. Experimental results demonstrate that a multi-sensor with a temperature coefficient of resistance of 3.82 × 10^-3 K^-1 and gauge factor of 30.6 can be successfully fabricated using one-step inkjet printing.

• Textile Coloration and Finishing
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• v.19 no.3
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• pp.18-25
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• 2007

The fixing behaviors of anthraquinone disperse dyes containing dimethylamino substituent, such as C. I. Disperse Violet 26(D.V.26) and C. I. Disperse Blue 14(D.V.14), or containing diamino substituent, such as C. I. Disperse Blue 73(D.B.73), and monochlorotriazinyl azo reactive dyes, such as C. I. Reactive Orange 13(R.O.13), C. I. Reactive Red 3(R.R.3). C. I. Reactive Yellow 2(R.Y.2) on polyester/cotton blend(P/C) fabrics were examined for the one-step printing of P/C fabrics. The high temperature steaming of $175^{\circ}C$ is the most satisfactory fixing method for P/C one-step printing with above disperse and reactive dyes among the four different fixing methods: $175^{\circ}C$ steaming, $102^{\circ}C$ steaming${\rightarrow}175^{\circ}C$ steaming, $190^{\circ}C$ thermosol, $102^{\circ}C$ steaming${\rightarrow}190^{\circ}C$ thermosol. $190^{\circ}C$ thermosol is unfit to fix R.R.3 and R.Y.2 whose heat stability is poor. It was found that D.V.26 and D.B.14 containing dimethylamino substituent are unstable for heat and alkali, but D.B.73 is stable for them to print P/C blend fabrics with R.O.13 which is also stable for heat. Therefore we found that D.B.73, R.O.13 and a pair of D.B.73 and R.O.13 were very suitable for one-step printing of P/C blend fabrics.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1087-1090
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• 2008

This paper presents the electro-luminescence (EL) display lamp which is patterned on a curved surface by the pad printing method. The printing methods, including the gravure, screen, flexo, inkjet, and pad printing, have an advantage of one-step direct patterning. However, in general, the printing and semi-conductor process, except pad printing method, cannot be applied for patterning on a curved surface. Thus, in this paper, we used pad printing method for patterning an EL display lamp on a curved surface. The EL display lamp consists of 5 layers: Bottom electrode; Dielectric layer; Phosphor; Transparent electrode; Bus electrode. Finally, we printed EL display lamp on a dish, which has a radius of curvature 80mm. The EL display lamp was driven at AC 200V of 1kHz.

• Journal of the Korea Fashion and Costume Design Association
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• v.12 no.2
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• pp.67-73
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• 2010

Whole process of textile printing is made by computer and it remarkably improves environment problem. This digital textile printing is becoming next step environment friendly textile printing method. But, still now range of textile possible for digital textile printing is limited, and also color analysis according to fiber types is not completed. The ink printed on the fabrics through DTP printer can be absorbed and fixed into textile without any blots by pre-treatment using suitable media solution for fabrics types. The chemical formulation of media solution used in the pre-treatment process varies according to the types of textiles and inks for DTP products. First, I studied reference books or articles about color analysis of digital textile printing. Second, I recorded pre-process, printing, post-process and coloring of silk, wool, nylon at same condition. After that, I analyzed $L^*\;a^*\;b^*$, Total K/S, ${\Delta}E$ and studied color intensity and coloring. According to this study, I suggested particular textile special for coloring and manual for affective coloring control. It showed that the performance of the digital printing on the Silk, Wool and Nylon blend fabrics treated by the media solution developed in this study was better than the one treated by the previous media solution for each single inks.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.40-44
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• 2011

Recent studies in crystalline silicon solar cell fabrication have been focused on high efficiency and low cost. However, the rising of the cost results in additional processes to approach high efficiency. The fabrication process also becomes complicated with additional technologies. In this paper, we studied the selective emitter formation with phosphorous paste to improve the conversion efficiency. Selective emitter formations like two-step diffusion or etch-back method require at least one more step compared in the conventional line since heavily and lightly doped area was needed to form separately.However,one-step diffusion process is the method diffusing heavily and lightly doped area at the same time only with additional screen-printing step. This study lays the foundation for the simple way to form the selective emitter.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.381-393
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• 2016

The new paradigm of 3D printing is that no one is clearly easy to regulate or estimate the impact adverse on existing industry or the form of new business models. Nevertheless, it will be judged that there is no person to deny about potential possibility of implicated 3D printing technology by industrial and business aspects. This study has the purpose and significance of that to suggest practical education which is available as practical application because new creative tools in design department are expected to have greater impact and use of 3D printing technology. Based on the analysis of research on the work process of 3D printing technology for this purpose, we composed the step-by-step curriculum linkages which combined theory and practice for student to create the well-made final output.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.144.1-144.1
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• 2016

We fabricate organic single crystal nanowire heterojunction p-n diode poly(3-hexylthiophene)(P3HT) and from Phenyl-C61-butyric acid methyl ester(PCBM) using by liquid-bridge mediated nanotransfer molding(LB-nTM) method. LB-nTM has been reported an one step direct printing method for making well-aligned nanowire arrays. Moreover, multi-patterning nanostructures can be fabricated with the consecutive printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as lateral organic p-n nanojunction diode. P3HT/PCBM nanowires heterojunction diode has rectifying behavior with on/off ratios of ~20.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.563-563
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• 2012

We report a one-step fabrication of single-crystal organic nanowire arrays on substrates using a new direct printing method (liquid-bridge-mediated nanotransfer moulding, LB-nTM), which can simultaneously enable the synthesis, alignment and patterning of the nanowires using molecular ink solutions. Two- or three-dimensional complex structures of various single-crystal organic nanowires were directly fabricated over a large area with a successive process. The position of the nanowires can be aligned easily on complex structures because the mold is movable on substrates before drying the polar liquid layer, which acts as an adhesive lubricant. This efficient manufacturing method can produce a wide range of optoelectronic devices and integrated circuits with single-crystal organic nanowires.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.578-578
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• 2012

Graphene, a flat one-atom-thick two-dimensional layer of carbon atoms, is considered to be a promising candidate for nanoelectronics due to its exceptional electronic properties. Most of all, future nanoelectronics such as flexible displays and artificial electronic skins require low cost manufacturing process on flexible substrate to be integrated with high resolutions on large area. The solution based printing process can be applicable on plastic substrate at low temperature and also adequate for fabrication of electronics on large-area. The combination of printed electronics and graphene has allowed for the development of a variety of flexible electronic devices. As the first step of the study, we prepared the gate electrodes by printing onto the gate dielectric layer on PET substrate. We showed the performance of graphene field-effect transistor with electrohydrodynamic (EHD) inkjet-printed Ag gate electrodes.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.158-158
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• 2011

A wide range of techniques for the direct-printing of functional materials have been developed for the fabrication of micro- and nanoscale structures and devices. Here we report a new direct patterning method, liquid bridge-mediated nanotransfer molding (LB-nTM), for the formation of two- or three-dimensional structures with feature sized as small as tens of nanometers over large areas up to 4". LB-nTM is based on the direct transfer of various materials from a mold to a substrate via a liquid bridge between them. The LB-nTM method was applied to the preparation of organic nanowire FETs on flexible substrates.