• ETRI Journal
• /
• 제42권2호
• /
• pp.272-281
• /
• 2020

Three-dimensional (3D) selfie services, one of the major 3D printing services, print 3D models of an individual's face via scanning. However, most of these services require expensive full-color supporting 3D printers. The high cost of such printers poses a challenge in launching a variety of 3D printing application services. This paper presents a stencil-based 3D facial relief creation method employing a low-cost RGBD sensor and a 3D printer. Stencil-based 3D facial relief is an artwork in which some parts are holes, similar to that in a stencil, and other parts stand out, as in a relief. The proposed method creates a new type of relief by combining the existing stencil techniques and relief techniques. As a result, the 3D printed product resembles a two-colored object rather than a one-colored object even when a monochrome 3D printer is used. Unlike existing personalization-based 3D printing services, the proposed method enables the printing and delivery of products to customers in a short period of time. Experimental results reveal that, compared to existing 3D selfie products printed by monochrome 3D printers, our products have a higher degree of similarity and are more profitable.

• 산업식품공학
• /
• 제21권1호
• /
• pp.12-21
• /
• 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.

• 대한방사선기술학회지:방사선기술과학
• /
• 제39권3호
• /
• pp.337-344
• /
• 2016

본 연구에서는 3차원(3-dimensional, 3D) 프린팅 기술로 출력된 팬톰에 대한 X선 투과성을 평가하고자 하였다. 3D 프린팅 방식은 용융적층조형(fused deposition modeling, FDM) 방식을 이용했으며 소재는 아크릴로나이트릴 뷰타다이엔 스타이렌(acrylonitrile butadiene styrene, ABS)을 사용하였다. 팬톰은 원통 모양으로 설계하였으며 전산화단층영상장비(computed tomography, CT)에서 획득한 단면영상으로 균일도를 측정하였다. X선 투과성 평가는 3D 출력된 팬톰 내부에 이온챔버를 삽입하여 실시하였다. 그 결과, 평균 균일도가 2.70 HU이었으며 기존 폴리메틸 메타크릴레이트(poly methyl methacrylate, PMMA) CT 팬톰과 3D 프린터로 출력된 팬톰에서 측정된 X선 투과성의 상관관계는 0.976로 높은 상관관계가 있는 것으로 나타났다. 향후 3D 프린팅 기술을 이용한 방사선정도관리 팬톰 제작에 기초자료로 활용할 수 있으리라 기대한다.

• Journal of International Society for Simulation Surgery
• /
• 제1권2호
• /
• pp.99-102
• /
• 2014

The skull defect can be made after the trauma, oncologic problems or neurosurgery. The skull reconstruction has been the challenging issue in craniofacial fields for a long time. So far the skull reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for skull reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile various types of allogenic and alloplastic materials have been also used. However, skull reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original skull anatomy as possible using the 3D printed titanium implant, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we fabricated Titanium implant to reconstruct three-dimensional orbital structure in advance, using the 3D printer. This prefabricated Titanium-implant was then inserted onto the defected skull and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

• 한국전자통신학회논문지
• /
• 제9권12호
• /
• pp.1415-1420
• /
• 2014

3D 프린터는 3D도면을 입력받아 적층가공 방식으로 재료를 쌓아 원하는 제품을 제작하는 프린터이다. 3D 프린터는 다양한 입체 제품을 출력할 수 있고, 짧은 시간 내에 제품 출력이 가능하여 다양한 분야에서 사용되고 있다. 이러한 3D 프린터는 다양한 종류의 출력방식과 재료가 있는데 본 논문에서는 이중 ABS(Acrylonitrile Butadiene Styrene)수지를 녹여 쌓는 FDM(Fused Deposition Modeling)방식을 고려한다. 이 방식을 사용한 3D 프린터는 고온에서 제품을 출력하여 짧은 시간 내에 냉각이 진행되는데, 이 과정에서 출력물의 크기나 주변 환경의 상태에 따라서 휘어짐 현상이 발생한다. 이러한 휘어짐 현상을 최소화하기 위해 현재 사용되고 있는 방법은 온도를 적정선으로 유지해주는 방식이다. 이 방식은 온도 유지를 위한 추가적인 장비가 필요하여 본 논문에서는 휘어짐 현상을 최소화하기 위한 3D 프린팅 기법을 제안한다. 제안된 방식은 제품의 최초설계 시 휘어짐 위치를 고려하여 적당한 구멍(홈)을 생성시켜 출력하는 방법을 기반으로 한다. 제안된 방법에 대한 수학적 모델을 제시하고, 성능평가를 위해 일반적인 방식을 사용한 출력물과 제안된 방법으로 설계한 출력물을 측정하고 분석한다.

• 한국전산구조공학회논문집
• /
• 제35권3호
• /
• pp.191-196
• /
• 2022

본 연구에서는 3D 프린팅 FDM 방식의 적층 방향에 따라 기계적 물성이 달라지는 이방성 특성을 확인하고 이를 이용하여 위상 최적설계를 수행하였다. 벤치마크 문제인 자동차 현가장치 부품 중 하나인 로어 컨트롤 암에 대하여 밀도법 기반 위상 최적설계를 수행하였으며, 외부 하중과 이방성 특성에 따라 위상 최적결과가 다르게 나타나는 것을 확인하였다. 이를 이용하여 최적화된 모델에 대하여 3D 프린터로 적층 방향을 달리하여 2가지 시험품을 제작하였으며 인장시험을 수행하였다. 시험시 3D 비접촉 변형률 측정기를 이용하여 변형률을 구하였으며 이를 CAE 응답해석으로 얻은 변형률과 비교한 결과가 정량 및 정성적으로 일치하는 것을 확인하였다. 3D 프린팅 적층 방향을 고려한 위상 최적모델의 인장 실험 결과를 통해 해당 최적설계 방법론의 유효성을 검증하였다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제28권1호
• /
• pp.24-31
• /
• 2024

기존 대부분의 3D 콘크리트 프린팅 연구는 모르타르를 재료로 활용하고 있다. 다만, 굵은 골재를 포함한 콘크리트에 비해 모르타르를 사용할 경우에는 높은 바인더 함량과 잔골재량으로 인하여 경제성이 저하될 수 밖에 없다. 따라서, 3D 프린팅 기술의 건설산업 적용 확대를 위해서는 굵은 골재를 사용한 콘크리트 3D 프린팅에 대한 연구가 요구된다. 본 연구에서는 굵은 골재가 포함된 3D 프린팅 용 콘크리트의 배합설계 프로세스를 제안하고자 하였다. 다양한 문헌연구 및 배합실험을 참고하여 3D 프린팅에 적합한 배합을 도출하였으며, 출력실험을 통하여 압출성을 검증하였다. 콘크리트 배합의 증점제(Viscosity modifying agent, VMA) 함량을 출력실험의 변수로 설정하였으며, 출력된 필라멘트의 치수 적합성, 골재분포도, 표면 품질을 평가하여 압출성능을 검증하였다. 실험결과, VMA의 함량이 높은 배합이 더 우수한 치수 적합성과 표면 품질을 보였으며, VMA 함량이 다름에도 불구하고 모든 배합에서 골재분포가 균등하게 나타났다. 실험결과를 바탕으로 굵은 골재가 포함된 콘크리트의 압출성을 향상 시킬 수 있는 배합설계 프로세스를 도출하였다.

• Journal of Microbiology and Biotechnology
• /
• 제32권12호
• /
• pp.1573-1582
• /
• 2022

In this study, we investigated the optimal conditions for 3D structure printing of alternative fats that have the textural properties of lard using beeswax (BW)-based oleogel by a statistical analysis. Products printed with over 15% BW oleogel at 50% and 75% infill level (IL) showed high printing accuracy with the lowest dimensional printing deviation for the designed model. The hardness, cohesion, and adhesion of printed samples were influenced by BW concentration and infill level. For multi-response optimization, fixed target values (hardness, adhesiveness, and cohesiveness) were applied with lard printed at 75% IL. The preparation parameters obtained as a result of multiple reaction prediction were 58.9% IL and 16.0% BW, and printing with this oleogel achieved fixed target values similar to those of lard. In conclusion, our study shows that 3D printing based on the BW oleogel system produces complex internal structures that allow adjustment of the textural properties of the printed samples, and BW oleogels could potentially serve as an excellent replacement for fat.

• 한국기계가공학회지
• /
• 제16권4호
• /
• pp.9-15
• /
• 2017

In hot forming process, the dies in which excessive worn or crack occurs is reused after repair. Generally hot forming dies are recycled through a welding repair method. Welding repair methods are highly dependent on the skills of engineer. It causes process defects such as dimensional defects and structural defects. Recently, the metal 3D printing method has been applied to the repair of used dies. The aim of this study is to evaluate the wear characteristics of AISI H13 tool steel repaired by 3D printing method. Three kinds of wear specimens were fabricated by using 3D printing, welding, and initial material. A pin-on-disk wear test was carried out to evaluate the wear characteristics. From the result of wear test, the wear characteristics of 3D printing method was superior to that of the welded material, and was similar to that of the initial material.

• 대한치과기공학회지
• /
• 제43권3호
• /
• pp.77-83
• /
• 2021

Purpose: The purpose of this in vitro study was to measure and compare the thickness-dependent color dimensions of digital light processing (DLP) three-dimensional (3D) printer and conventional interim restorative resin. Methods: Specimens (N=60) were fabricated using either subtractive manufacturing (S group) or DLP 3D printing (D group) material. All milled and 3D-printed specimens were allocated into three different groups (n=10) according to different thicknesses as follows: 1.0, 1.5, and 2.0 mm. Color measurements in the CIELab coordinates were made using a spectrophotometer under room light conditions (1,003 lux). The color differences (𝚫E^*) between the specimen and control target data were calculated. Data were analyzed using the oneway analysis of variance (ANOVA). Post hoc comparisons were conducted using Tukey's honestly significant difference method (α=0.05 for all tests). Results: The 𝚫L^*, 𝚫a^*, 𝚫b^*, and 𝚫E^* values of interim restorative resin produced by DLP 3D printing were obtained in terms of the specimen's thickness increased compared with the increases by subtractive manufacturing. When the thickness was similar, the color difference between subtractive manufacturing and DLP 3D printing was ≥5.5, which is a value required by the dentist for remanufacturing. Conclusion: Color was influenced by the thickness of the interim restorative resin produced by DLP 3D printing.