• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.632-632
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• 2013

We generated single-crystal organic nanowire arrays using a direct printing method (liquidbridge- mediated nanotransfer molding) that enables the simultaneous synthesis, alignment and patterning of nanowires from molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. The position of the nanowires on complex structures is easy to adjust, because the mold is movable on the substrates before the polar liquid layer, which acts as an adhesive lubricant, is dried. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with twoor three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate all-organic nanowire field-effect transistors that are integrated into device arrays and inverters on flexible plastic substrates.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.256-257
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• 2006

3D printing of NiTi alloys has been successfully achieved. A novel printing process has been developed and used, which consists in selective deposition of a solvent on a granule bed. The granules are composed of metal powders and thermoplastic binder, which are mixed and sieved by conventional methods. A sound green strength is obtained after solvent evaporation. Sintered parts exhibit good density, proper phase composition and shape memory behaviour.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.266.1-266.1
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• 2013

Large-scale single-crystal organic nanowire arrays were generated using a direct printing method (liquidbridge- mediated nanotransfer molding) that enables the simultaneous synthesis, alignment and patterning of nanowires from molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with two- or three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate all-organic nanowire field-effect transistors that are integrated into device arrays and inverters on flexible plastic substrates.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.104-109
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• 2019

Reverse engineering techniques using 3D scanners and 3D printing technologies are being used in various industries. In this paper, the three-dimensional model is designed for automotive hub parts through 3D scanning and reverse engineering, and the design of hub parts is intended to be printed on FDM-style 3D printers to measure and analyze the dimensions of hub parts designed for reverse design and 3D printed hub parts. Experimental result have shown that the dimensions of 3D printed hub parts are small compared to those of the reverse-engineered dimensions, which are due to the shrinkage of filament materials in 3D printing.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.4
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• pp.293-298
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• 2017

In this study, we developed a 3D chocolate printer and studied the conditions needed for chocolate printing. Because chocolate is a mixture of cocoa mass, cocoa butter and sugar particles, its properties vary with temperature, and care is required in melting and extrusion. A chocolate supply unit is composed of a heating block and a syringe pump. It is integrated with a 3-axis linear robot. In order to be more accurate than the existing 3D chocolate printer is, the system was configured so that the printing line width became $430{\mu}m$. Printing performance was studied according to various parameters. The condition needed for printing lines with a stable width was discovered by the experimental design method and has been confirmed by a 2D line test. These 3D printing experiments showed that it was possible to build a 3D shape with an inclination angle of up to $45^{\circ}$ without support. Further, chocolate printing of a 3D shape has been successfully verified with the developed system.

• Journal of Powder Materials
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• v.24 no.3
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• pp.187-194
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• 2017

Selective laser melting (SLM) can produce a layer of a metal powder and then fabricate a three-dimensional structure by a layer-by-layer method. Each layer consists of several lines of molten metal. Laser parameters and thermal properties of the materials affect the geometric characteristics of the melt pool such as its height, depth, and width. The geometrical characteristics of the melt pool are determined herein by optical microscopy and three-dimensional bulk structures are fabricated to investigate the relationship between them. Powders of the commercially available Fe-based tool steel AISI H13 and Ni-based superalloy Inconel 738LC are used to investigate the effect of material properties. Only the scan speed is controlled to change the laser parameters. The laser power and hatch space are maintained throughout the study. Laser of a higher energy density is seen to melt a wider and deeper range of powder and substrate; however, it does not correspond with the most highly densified three-dimensional structure. H13 shows the highest density at a laser scan speed of 200 mm/s whereas Inconel 738LC shows the highest density at 600 mm/s.

• The Research Journal of the Costume Culture
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• v.29 no.4
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• pp.585-602
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• 2021

The purpose of this study is twofold: First, to develop new sustainable design methods (aligned with ethnic elements and traditional culture) combined with three-dimensional digital clothing technology throughout the design process, which can be presented as guideline materials for various fashion designs to be developed in contemporary sensibilities. Second, it is the intention to produce creative fashion designs by incorporating the characteristics and methods of Miao's Huangping batik dyeing technique and to present various possibilities in the fashion design field. The overall design characteristics sought by Miao minority are in line with the complex terrain and the ecological and climatic conditions. Miaoist batik dyeing (registered as part of Chinese national intangible cultural heritage) features unique production methods and patterns. The study results are as follows. First, this attempt has enabled understanding of the national costume culture as Chinese Miao's traditional cultural heritage to be promoted, while the direction of contemporary design development using traditional elements has been presented. Second, the study demonstrated new and innovative expressions and styles relying on three-dimensional digital contouring technology and identified the possibility of developing various designs. Third, it was confirmed that the dyed batik pattern design created by the three-dimensional digital contouring technology could be recombined or expanded as digital printing to express the traditional ethnic designs in a practical manner utilizing digital printing techniques based on traditional characteristics.

• Archives of Craniofacial Surgery
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• v.16 no.1
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• pp.11-16
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• 2015

Background: Source material used to fill calvarial defects includes autologous bones and synthetic alternatives. While autologous bone is preferable to synthetic material, autologous reconstruction is not always feasible due to defect size, unacceptable donor-site morbidity, and other issues. Today, advanced three-dimensional (3D) printing techniques allow for fabrication of titanium implants customized to the exact need of individual patients with calvarial defects. In this report, we present three cases of calvarial reconstructions using 3D-printed porous titanium implants. Methods: From 2013 through 2014, three calvarial defects were repaired using custom-made 3D porous titanium implants. The defects were due either to traumatic subdural hematoma or to meningioma and were located in parieto-occipital, fronto-temporo-parietal, and parieto-temporal areas. The implants were prepared using individual 3D computed tomography (CT) data, Mimics software, and an electron beam melting machine. For each patient, several designs of the implant were evaluated against 3D-printed skull models. All three cases had a custom-made 3D porous titanium implant laid on the defect and rigid fixation was done with 8 mm screws. Results: The custom-made 3D implants fit each patient's skull defect precisely without any dead space. The operative site healed without any specific complications. Postoperative CTs revealed the implants to be in correct position. Conclusion: An autologous graft is not a feasible option in the reconstruction of large calvarial defects. Ideally, synthetic materials for calvarial reconstruction should be easily applicable, durable, and strong. In these aspects, a 3D titanium implant can be an optimal source material in calvarial reconstruction.

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.232-236
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• 2020

Three-dimensional (3D) multilayered Pt electrodes were fabricated to develop a porous electrode using a pattern-transfer printing process. The Pt thin films were deposited using a transferred sputtering pattern having a 250 nm line width on the substrate, and the uniform line patterns were efficiently transferred using our proposed method. Temperature-programmed desorption (TPD) analyses were used to evaluate the porosity of the electrodes. It was possible to distinguish between two resolved maxima at 168 and 227 ℃, which could be described in terms of desorption reactions on the Pt (111) planes. The results of the TPD analysis of the 3D and multilayered Pt electrodes prepared through transfer printing were compared to those of an electrode fabricated through screen printing using a commercial Pt-carbon paste commonly used as porous electrodes. It was confirmed that the 3D multilayered electrodes exhibited a desorption concentration approximately 100 times higher than that of the Pt-carbon composite electrode, and the desorption concentration increased by approximately 0.02 mg/mol per layer. The 3D multilayered electrode effectively functions as a porous electrode and a catalyst.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.71-78
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• 2018

In this study, human mimic phantoms outputted by three-dimensional (3D) printing technology are reported. Polylactic acid and a personal 3D printer - fused deposition modeling (FDM) - are used as the main material and the printing device. The output of human mimic phantoms performed in the following order: modeling, slicing and G-code conversion, output variable setting, 3D output, and post-processing. The students' learning satisfaction (anatomical awareness, study interest) was measured on 5-point Likert scale. After that, Twenty of those phantoms were outputted. The total output took 11,691 minutes (194 hours 85 minutes) and the average output took 584.55 minutes (9 hours 7 minutes). The filament used for the experiment was 2,390.2 g, and the average use of the filament was 119.51 g. The learning satisfaction of anatomical awareness was 4.6 points on the average and the interest of the class was on average 4.5 points. It is expecting that 3D printing technology can enhance the learning effect of imaging anatomy education.