• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.140-147
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• 1995

This paper deals with conversion from the STL file to the Slice to the Slice cross-sectional information for Stereolithography. The STL file is widely used for Stereolithography, but it is very difficult to convert STL file into Slice file directly. Because it consists of an ordered list of triangular net without any topological information other than the orientation of each facet. So, The system is accomplished by data flow through several intermediate stages such as Reference. SL1. .SL2L. .SL3. and .SLC file. The data processing is performed in 5 steps: 1) Create a Reference file including common information. 2) Modify STL file within the effective range of SL machine. 3) Calculate a point of intersection between plane equation and line equation. 4) Sort z values in ascending order using quick sort algorithm. 5) Search the adjacent points and formulate a closed loop usingsingly linked linear list. The system is developed by using Borland C++ 3.1 compiler in the environment of Pentium PC, and verified to be satisfactory by making some prototypes of electric household appliances.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.305-305
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• 2004

쾌속조형 기술은 3차원 CAD 데이터를 일정한 두께 간격으로 슬라이싱한 각 층을 다양한 방법으로 만들고, 이러한 층을 한층씩 적층하여 원하는 3차원 형상을 신속하게 제작하는 기술이다. 쾌속 조형법은 초기에는 광(beam)에 의해 형상이 만들어진다고 하여 광조형법이라고 불렸다. 그 후 시작품(Prototype)을 신속(Rapid)하게 제작할 수 있다는 사실로부터 'Rapid Prototyping' 또는 '쾌속 조형법' 이라고 불려지게 되었다.(중략)

• Journal of the Korean Society for Precision Engineering
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• v.13 no.12
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• pp.142-150
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• 1996

Nowadays, as the development paeiod of new products becomes even shorter, the importance of Rapid Prototyping Technology(RPT) has been rapidly increased. The major application of RPT is an early verification of product designs and quick production of prototypes for testing. Moreover, RPT is applied not only as a second tooling process such as mold making and investment casting but also as a creating some physical structure in medical field. Despite the remarkable progress of RPT, it is required to improve various problems resulting from application such as production time, accuracy and materials. This paper presents a laser scan path generation for accuracy of stereolithographicparts The methodology of laser scan path generation is discussed based on the stereolithography, The procedure of this research is as follows : 1) Input laser scanning conditions such as a laser beam diameter and a laser scanning interval, 2) Reconstruct original contours without self intersecting offset, 3) Calculate offset about reconstructed contours, 4) Calculate intersection points between horizontal or vertical lines and offset contours for internal hatch, 5) Decide laser shutter on/off points. The algorithm developed and programmed by C language is verified as an efficient method after testing a number of STL files of mechanical parts.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.174-179
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• 2006

The curing characteristics of a photocurable resin are critical factors that often decide the ultimate resolution and structural sharpness of a final product fabricated by microstereolithography$(\mu-STL)$. In this study, we investigated the curing characteristics of the FA1260T photopolymer under a visible laser light of 42nm wavelength. Modification of the curing property of the FA1260T is attempted to reduce the cure depth $(D_c)$ by adding a radical quencher to the resin. Also, an organic solvent was used to reduce the resin viscosity for an improvement of the flatness of the liquid surface during layer-by-layer curing. As a result, the minimum $D_c$ has been reduced over a factor of 3 with no abrupt increase. Samples of three dimensional microstructures fabricated using the modified FA1260T are presented.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.188-195
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• 2004

In this paper, we fabricated fluidic devices like micro-channel, pump, mixer and particular gas separator with the technology of stereolithouaphy using RP(rapid-prototyping). The fabricated fluidic devices are expected to be applied to develop Lab-on-a chip type liquid analyzer. Stereolithography technology seems effective for fabricating MEMS(Micro Electro Mechanical System) with complicated structure because it makes three dimensional fabrication possible but, exclusive devices are needed to be developed fur fabricating even more microscopic MEMS structure.

• The Optical Journal
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• s.148
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• pp.16-18
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• 2013

3D 프린팅은 디지털 디자인 데이터로 3차원의 물체를 만들어내는 기술로, 공장 없이도 제품을 만들 수 있는 미래 기술로 불린다. 프린터에 넣는 재료가 다양해지고 실제 이용할 수 있는 범위가 넓어지면서 미래 고부가가치 산업으로도 꼽힌다. 미국 컨설팅기관 홀러스 어소시에이츠(Wohlers Associates)는 세계 3D 프린터 시장이 연평균 29%씩 성장할 것이며 2015년 37억 달러에서 2019년이 되면 65억 달러를 넘어설 것으로 내다봤다. 미국, 중국, 일본 등은 이미 정부와 민간 차원에서 산업활성화 노력이 활발하다. 3D 프린팅 기술의 국산화에 성공하고 세계 시장에 도전하고 있는 중소기업이 있어 화제다. 한국 최초로 산업용 3D 프린팅 기술을 개발한 캐리마가 바로 그 주인공이다. 이 회사는 국내 유일 광조형 3D 프린터 원천기술을 바탕으로 제품을 개발해 최근 양산 체제를 갖추었다. '가진 것이라곤 장래가 불투명한 기술밖에 없는 중소 기업'에서 '국내 유일의 3D 프린터 제조업체'로 불리게된 캐리마를 찾아가 이병극 대표의 이야기를 들어봤다.

• Journal of the Semiconductor & Display Technology
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• v.8 no.4
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• pp.7-13
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• 2009

The slender device(long length and thin width) manufactured by stereolithography process suffers from large curl distortion. This paper adapts two control parameters such as a critical exposure and a penetration depth. The measurement of the test parts dimension are carried out by reverse engineering method with the optical 3-dimensional measurement equipment. We investigate how each parameter contributes to the part accuracy and estimates the optimal set of parameters which minimizes the dimensional error of the test parts. Finally, As being an the RAM slot as being an example of the slender device, the RAM slot is made with the optimal values of control parameter and the results are investigated

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.93-99
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• 2011

This paper presents a new type of optical silicon accelerometer using deep reactive ion etching (DRIE) and micro-stereolithography technology. Optical silicon accelerometer is based on a mass suspended by four vertical beams. A vertical shutter at the end of the mass can only moves along the sensing axis in the optical path between two single-mode optical fibers. The shutter modulates intensity of light from a laser diode reaching a photo detector. With the DRIE technique for (100) silicon, it is possible to etch a vertical shutter and beam. This ensures low sensitivity to accelerations that are not along the sensing axis. The microstructure for sensor packaging and optical fiber fixing was fabricated using micro stereolithography technology. Designed sensors are two types and each resonant frequency is about 15 kHz and 5 kHz.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.624-631
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• 2004

In this paper, new replication techniques fur a metal microcomponent having a real 3D shape were introduced. Helical gear was selected as one of a real 3D microcomponents for this study. The helical gear, which was made of photo-curable resin, was fabricated as a master pattern by microstereolithography technology. Then, a silicone rubber mold was fabricated from the master pattern. Lastly, a final bismuth alloy pattern was transferred from the silicone rubber mold by the microcasting process. In this paper, the replication technique is described in detail from the master pattern to the final pattern with some investigation on factors related to the technique.

• Korean Journal of Materials Research
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• v.29 no.4
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• pp.221-227
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• 2019

This study examines the role of the nano- and micro-particle ratio in dispersion stability and mechanical properties of composite resins for SLA(stereolithography) 3D printing technology. VTES(vinyltriethoxysilane)-coated $ZrO_2$ ceramic particles with different nano- and micro-particle ratios are prepared by a hydrolysis and condensation reaction and then dispersed in commercial photopolymer (High-temp) based on interpenetrating networks(IPNs). The coating characteristics of VTES-coated $ZrO_2$ particles are observed by FE-TEM and FT-IR. The rheological properties of VTES-coated $ZrO_2/High-temp$ composite solution with different particle ratios are investigated by rheometer, and the dispersion properties of the composite solution are confirmed by relaxation NMR and Turbiscan. The mechanical properties of 3D-printed objects are measured by a tensile test and nanoindenter. To investigate the aggregation and dispersion properties of VTES-coated $ZrO_2$ ceramic particles with different particle ratios, we observe the cross-sectional images of 3D printed objects using FE-SEM. The 3D printed objects of the composite solution with nano-particles of 80 % demonstrate improved mechanical characteristics.