• Korean Journal of Materials Research
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• v.23 no.10
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• pp.586-591
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• 2013

The printing of nanomaterials onto certain substrates is one of the key technologies behind high-speed interconnection and high-performance electronic devices. For the printing of next-generation electronic devices, a printing process which can be applied to a flexible substrate is needed. A printing process on a flexible substrate requires a lowtemperature, non-vacuum process due to the physical properties of the substrate. In this study, we obtained well-ordered Ag nanowires using modified gravure printing techniques. Ag nanowires are synthesized by a silver nitrate ($AgNO_3$) reduction process in an ethylene glycol solution. Ag nanowires were well aligned by hydrodynamic force on a micro-engraved Si substrate. With the three-dimensional structure of polydimethylsiloxane (PDMS), which has an inverse morphology relative to the micro-engraved Si substrate, the sub-micron alignment of Ag nanowires is possible. This technique can solve the performance problems associated with conventional organic materials. Also, given that this technique enables large-area printing, it has great applicability not only as a next-generation printing technology but also in a range of other fields.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.50-56
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• 2020

Currently, 3D printing technology is a new revolutionary additive manufacturing process that can be used for making three dimensional solid objects from digital films. In 2019, this 3D printing technology spreading vigorously in production parts (57%), bridge production (39%), tooling, fixtures, jigs (37%), repair, and maintenance (38%). The applications of 3D printing are expanding to the defense, aerospace, medical field, and automobile industry. The raw materials are playing a key role in 3D printing. Various additive materials such as plastics, polymers, resins, steel, and metals are used for 3D printing to create a variety of designs. The main advantage of the green cement for 3D printing is to enhance the mechanical properties, and durability to meet the high-quality material using in construction. There are several advantages with 3D printing is a limited waste generation, eco-friendly process, economy, 20 times faster, and less time-consuming. This research article reveals that the role of green cement as an additive material for 3D printing.

• Journal of Technologic Dentistry
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• v.44 no.3
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• pp.76-80
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• 2022

Purpose: The purpose of this study is to analyze the depth according to curing using photocurable resin for dental three-dimensional printing. Methods: A stainless mold with a height of 4 mm was prepared. Ultraviolet (UV) polymerization resin was injected into the mold. Photocuring was then performed for 5 minutes using a photopolymerizer, and the height was measured using a digital measuring instrument (first group). Second, light polymerization was also performed outside the mold for 5 minutes, and the height was measured using a digital measuring instrument. Third, light polymerization was further performed for 5 minutes, and the height was measured using a digital measuring instrument. Statistical analysis was performed with the Kruskal-Wallis test, which is a nonparametric test (α=0.05). Results: The third group had the largest measurement length, whereas the first group had the smallest. However, the difference between groups was not statistically significant (p>0.05). The color of the first group was different from that of the second and third groups. Conclusion: All of the 4-mm-thick photocured specimens had a curing reaction, but the part that was not directly irradiated with UV did not show its original color.

• Archives of Plastic Surgery
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• v.43 no.4
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• pp.379-381
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• 2016

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.4
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• pp.169-170
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• 2015

• Food Engineering Progress
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• v.21 no.1
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• pp.12-21
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• 2017

Foods are becoming more customized and consumers demand food that provides great taste and appearance and that improves health. Food three-dimensional (3D)-printing technology has a great potential to manufacture food products with customized shape, texture, color, flavor, and even nutrition. Food materials for 3D-printing do not rely on the concentration of the manufacturing processes of a product in a single step, but it is associated with the design of food with textures and potentially enhanced nutritional value. The potential uses of food 3D-printing can be forecasted through the three following levels of industry: consumer-produced foods, small-scale food production, and industrial scale food production. Consumer-produced foods would be made in the kitchen, a traditional setting using a nontraditional tool. Small-scale food production would include shops, restaurants, bakeries, and other institutions which produce food for tens to thousands of individuals. Industrial scale production would be for the mass consumer market of hundreds of thousands of consumers. For this reason, food 3D-printing could make an impact on food for personalized nutrition, on-demand food fabrication, food processing technologies, and process design in food industry in the future. This article review on food materials for 3D-printing, rheology control of food, 3D-printing system for food fabrication, 3D-printing based on molecular cuisine, 3D-printing mobile platform for customized food, and future trends in the food market.

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.204-205
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• 2005

Studies on display has been requested some major changes due to the high growth of the handheld terminal market. Therefore, the self emitting OLED(Organic Light Emitting Diode) has been interested as a next generation flat plane display because of its preeminent characteristics such as quick response characteristics, higher performance viewing angle, low power consumption, and panel floating. However, a trend of the display market is moving to three dimensional image processing instead of two dimensional flat display and various researches on display using hologram makes up for the difficulty in three dimensional display using typical flat display. In this study the Lenticular Screen Printing method is presented so that it can be applicable to organic semiconductor display devices and makes possible three dimensional display using flat display for complement the drawback of inorganic semiconductor.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.62-72
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• 2015

Interest in three-dimensional (3D) printing processes has grown significantly, and several types have been developed. These 3D printing processes are classified as Selective Laser Sintering (SLS), Stereo-Lithography Apparatus (SLA), and Fused Deposition Modeling (FDM). SLS can be applied to many materials, but because it uses a laser-based material removal process, it is expensive. SLA enables fast and precise manufacturing, but available materials are limited. FDM printing's benefits are its reasonable price and easy accessibility. However, metal printing using FDM can involve technical problems, such as suitable component supply or the thermal expansion of the heating part. Thus, FDM printing primarily uses materials with low melting points, such as acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) resin. In this study, an FDM process for enabling metal printing is suggested. Particularly, the nozzle and heatsink for this process are focused for stable printing. To design the nozzle and heatsink, multi-physical phenomena, including thermal expansion and heat transfer, had to be considered. Therefore, COMSOL Multiphysics, an FEM analysis program, was used to analyze the maximum temperature, thermal expansion, and principal stress. Finally, its performance was confirmed through an experiment.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1415-1420
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• 2014

3D printer is based on an additive manufacturing technology, which helps in creating the three-dimensional object using a 3D drawing. It is used in various fields, because it prints out a variety of three-dimensional products in a short period of time. In this paper, we consider a technique using the FDM(Fused Deposition Modeling) method by dissolving the ABS(Acrylonitrile Butadiene Styrene) resin among a diversity of printing technique and materials. This kind of the 3D printer prints out a product in high temperature and cools down it. In this process, a flection phenomenon is occurred according to the size of the printing product and the surrounding environment. Conventional methods for mitigating this phenomenon maintain the temperature at the optimum level, but they require using additional devices. In order to minimize the flection phenomenon in 3D printing products without additional devices, in this paper, we propose a noble technique, which creates holes on suitable positions when they are designed by 3D drawing tools. Also, we suggest mathematical model for the proposed method, and measure and analyse a printing output using a proposed technique.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.191-196
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• 2022

In this study, the anisotropic mechanical property of fused deposition modeling three-dimensional (3D) printing based on lamination direction was verified by a tensile test. Moreover, the property was applied to solid isotropic materials with penalization-based topology optimization. The case of the lower control arm, one of the automotive suspension components, was considered as a benchmark problem. The optimal topological results varied depending on the external load and anisotropic property. Based on these results, two test specimens were fabricated by varying the lamination direction of 3D printing; a tensile test utilizing 3D non-contact strain gauge was also conducted. The measured strain was compared with that obtained by computer-aided engineering response analysis. Quantitatively, the measurement and analysis results are found to have good agreement. The effectiveness of topology optimization considering the lamination direction of 3D printing was confirmed by the experimental result.