The Experts below are selected from a list of 1425 Experts worldwide ranked by ideXlab platform
Cho-pei Jiang - One of the best experts on this subject based on the ideXlab platform.
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Development of a novel two‐laser beam Stereolithography System
Rapid Prototyping Journal, 2011Co-Authors: Cho-pei JiangAbstract:Purpose – The purpose of this paper is to develop a novel two‐laser beam Stereolithography System which has the advantages of low cost, fabrication time reduction and high accuracy.Design/methodology/approach – The wavelengths of the two semiconductor laser beams are determined to be 405 nm (blue light) and 532 nm (green light), respectively, according to the relative absorbance rate of the visible‐light curable resin (NAF202) used. The blue light laser is suitable for scanning the contour of objects because of its fast absorbance, thus giving a narrow cured depth. The green light laser is better suited to scanning the internal crosshatch to condense the fabrication time because of its deep penetration and its high power results in a wide cured width. A photoabsorber, carbon powder with an average diameter of 0.1 μm, is adopted to control the cured layer thickness. An adaptive crosshatch technique is introduced and applied to the fabrication process. Two benchmarks are proposed and fabricated using the de...
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development of a novel two laser beam Stereolithography System
Rapid Prototyping Journal, 2011Co-Authors: Cho-pei JiangAbstract:Purpose – The purpose of this paper is to develop a novel two‐laser beam Stereolithography System which has the advantages of low cost, fabrication time reduction and high accuracy.Design/methodology/approach – The wavelengths of the two semiconductor laser beams are determined to be 405 nm (blue light) and 532 nm (green light), respectively, according to the relative absorbance rate of the visible‐light curable resin (NAF202) used. The blue light laser is suitable for scanning the contour of objects because of its fast absorbance, thus giving a narrow cured depth. The green light laser is better suited to scanning the internal crosshatch to condense the fabrication time because of its deep penetration and its high power results in a wide cured width. A photoabsorber, carbon powder with an average diameter of 0.1 μm, is adopted to control the cured layer thickness. An adaptive crosshatch technique is introduced and applied to the fabrication process. Two benchmarks are proposed and fabricated using the de...
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Accelerating fabrication speed in two-laser beam Stereolithography System using adaptive crosshatch technique
The International Journal of Advanced Manufacturing Technology, 2010Co-Authors: Cho-pei JiangAbstract:The aim of this research is to develop a novel two-laser beam Stereolithography System. The wavelengths of the two semiconductor laser beams are determined to be 405 nm (blue light) and 532 nm (green light), respectively, according to the relative absorbance rate of used visible light curable resin. The blue light laser is suitable for scanning contour of objects because of its fast absorbance, thus giving a narrow cured depth. The green light laser is better suited for scanning the internal crosshatch for condensing the fabrication time because its high power results in a wide cured width and deep penetration. The influence of the photoabsorber, carbon powder with average diameter of 0.1 µm, is discussed and an optimal weight percentage of 1.5 is specified for controlling cured thickness. An adaptive crosshatch technique is introduced and applied to the fabrication process. In addition, a turbine is fabricated using the proposed approach for comparison with the E-DARTS System in terms of fabrication capability. Results show that the developed System can fabricate objects quickly with high accuracy.
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Optimization of scanning path for reducing fabrication time in a novel two-laser beam Stereolithography System
2010Co-Authors: Cho-pei Jiang, Chang-cheng Chen, Yung-chang ChengAbstract:The aim of this study is to develop a novel two-laser beam (TLB) Stereolithography System and to optimize scanning path for shortening the fabrication time using adaptive crosshatch technique. In the development of TLB System, the wavelengths of the two semiconductor laser beams are determined to be 405 nm (blue light) and 532 nm (green light), respectively, according to the relative absorbance rate of used visible-light curable resin. The blue light laser is suitable for scanning the object contour due to the fast absorbance and caused a narrow cured depth. The green light laser is used for scanning the internal crosshatch for condensing the fabrication time because its high power results in a wide cured width and deep penetration. The influence of photoabsorber, carbon powder with average diameter of 0.1 micrometer, is discussed and specified an optimal weight percentage of 1.5 for controlling cured thickness. An adaptive crosshatch technique is introduced and applied into the fabrication process. In addition, two fan objects with seven blades are fabricated according to the raster scan and adaptive crosshatch scan, respectively. Consequently, the developed System fabricates object quickly with a high accuracy and adaptive crosshatch significantly reduces fabrication time.
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Development of Stereolithography Simulation Process Based on the Dynamic Finite Element Method
Key Engineering Materials, 2007Co-Authors: You-min Huang, Cho-pei JiangAbstract:In this study, a general simulation code is developed to analyze the shrinkage effect of polymerization and optimize the fabrication parameters including the scanning path, exposure time and scanning speed for the Stereolithography System. The code is based on the dynamic finite element method. Liquid element is preconstructed without curing properties till the absorption energy exceeds the critical value of dynamic stiffness matrix assembling. A unit element block is utilized with a weight coefficient for expressing a laser Gaussian energy distribution during the discretizing of the scanning path into increments. A fan blade is proposed to validate the agreement between the simulation and experimental results. The prototype is a fabrication and the surface of blade was measured by the digitizing System ATOS (Advanced TOpometric Sensor) for comparing the deformation with analysis prediction. Consequently, the simulated result closely conforms to the experimental result.
Soshu Kirihara - One of the best experts on this subject based on the ideXlab platform.
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Creation of Titania Artificial Interfaces with Geometric Patterns by Using MicroStereolithography and Aqueous Solution Techniques
International Journal of Applied Ceramic Technology, 2013Co-Authors: Soshu Kirihara, Yousuke Itakura, Satoko TasakiAbstract:Titania micro patterns with periodic arrangements were formed on glass substrates successfully for electromagnetic wave energy resonations and localizations in terahertz frequency ranges. Geometric arrangements of acryl polygon tablets with titania particles dispersions by using micro patterning Stereolithography. Moreover, periodically arranged full titania tablets with anatase phase were created homogeneously though liquid phase crystal depositions of water solvent processes under micro templates fabricated by using the Stereolithography System. The terahertz wave properties were measured and simulated by a using time domain spectroscopic System and finite difference time domain method. The terahertz waves having micrometer order wavelengths and belonging in far-infrared frequency ranges are expected to apply for various types of novel sensors which can detect micro cracks on materials surfaces, micro defects in electric devices, bacteria in foods, and cancer cells in human skins.
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Creation of Titania Artificial Interfaces with Geometric Patterns by Using Micro Stereolithography and Aqueous Solution Techniques
Additional Conferences (Device Packaging HiTEC HiTEN and CICMT), 2012Co-Authors: Soshu Kirihara, Yousuke Itakura, Satoko TasakiAbstract:Titania micro patterns with periodic arrangements were formed on glass substrates successfully for electromagnetic wave energy resonations and localizations in terahertz frequency ranges. Geometric arrangements of acryl polygon tablets with titania particles dispersions by using micro patterning Stereolithography. Moreover, periodically arranged full titania tablets with anatase phase were created homogeneously though liquid phase crystal depositions of water solvent processes under micro templates fabricated by using the Stereolithography System. The terahertz wave properties were measured and simulated by a using time domain spectroscopic System and finite difference time domain method. The terahertz waves having micrometer order wavelengths and belonging in far-infrared frequency ranges are expected to apply for various types of novel sensors which can detect micro cracks on materials surfaces, micro defects in electric devices, bacteria in foods, and cancer cells in human skins.
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Application 52 – Development of photonic crystal resonators for terahertz wave sensing by using nanoparticle Stereolithography
2012Co-Authors: Soshu KiriharaAbstract:Abstract Photonic crystals with periodic variations in dielectric constants can exhibit forbidden gaps in transmission spectrum to totally reflect electromagnetic waves through Bragg diffraction (Yablonovitch, 1987). Through introductions of artificial defects of air cavities into the periodic arrangement, localized modes are formed in the photonic bandgaps. These structural defects can localize and amplify electromagnetic wave energies at the specific frequencies and wavelengths corresponding to the sizes and dielectric constants of the resonation domains. For the last few decades, the photonic crystal has been expected to be applied for various microwave devices of resonators, filters, and directional antennas (Noda, 2000). Especially, micrometer order ceramic lattices with diamond structures were fabricated successfully by using nanoparticle Stereolithography to create the perfect photonic bandgaps and reflect the electromagnetic waves totally in all directions (Kirihara and Miyamoto, 2009). The lattice constant of the diamond structure and the aspect ratio of the dielectric lattice were designed as 500 μm and 1.5, respectively. The whole size of the crystal component was 5 mm × 5 mm × 1 mm consisting of 10 × 10 × 2 unit cells. Fig. 43.1 shows a schematic illustration of the Stereolithography System. Photosensitive acrylic resins including alumina particles of 170 nm in average diameter at 40% in volume content were supplied on a glass substrate from a dispenser nozzle by the air pressure. This paste was spread uniformly by using a mechanically controlled knife edge. The thickness of each layer was set at 15 μm. Two-dimensional solid patterns are obtained by a light-induced photopolymerization. High-resolution image has been achieved by using a digital micromirror device. In this optical device, microaluminum mirrors of 14 μm in edge length were assembled with 1024 × 768 in numbers. Each mirror can be tilted independently by piezoelectric actuating. Through the layer stacking, the acrylic resin component with the alumina particle dispersion was obtained. The composite precursor was dewaxed at 600°C for 2 h and sintered at 1500°C for 2 h in the air atmosphere. Fig. 43.2 shows the alumina lattice with the diamond structure fabricated by ceramic powder sintering. No cracks or deformations were observed in the obtained components. The average linear shrinkage was 25%. The lattice constant of the sintered sample was 375 μm. The relative density of the sample reached 97.5%.
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Microwave Emission from Metal Photonic Crystals Fabricated by using Stereolithography
Ferroelectrics, 2009Co-Authors: Daisuke Sano, Soshu KiriharaAbstract:Micro-scale photonic crystals composed of pure copper for microwave emission control were fabricated by using micro-Stereolithography System and sintering process. As a crystal structure, we designed diamond lattice structure with or without stretched lattice spacing. Diamond lattices exhibited common bandgap where electromagnetic wave can not propagate at any direction. Stretched lattices showed directional transmission property. Simulated and measured transmission properties of microwave propagating through the metal photonic crystals showed good agreements.
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Terahertz wave behaviours in ceramic and metal structures fabricated by spatial joining of micro-Stereolithography
Journal of Physics: Conference Series, 2009Co-Authors: Soshu Kirihara, Toshiki Niki, M. KanekoAbstract:We have newly developed micro-Stereolithography System to realize freeform fabrication of micrometer order 3D metal structures. In this process, the photo-sensitive resin paste mixed with nanometer sized ceramic and metal particles was spread on a glass substrate with 10 μm in layer thickness by using a mechanical knife edge, and two-dimensional images of UV ray were exposed using DMD (Digital Micro-mirror Device) with 2 μm in part accuracy. Through the layer by layer stacking process, micrometer order three-dimensional objects were formed. Dense metal structures could be obtained by dewaxing and successive sintering of the formed objects. In our recent investigation, micro photonic crystals with lattice structures of alumina or pure copper were fabricated in order to control electromagnetic wave propagation in a terahertz (THz) frequency range. The micro photonic crystals with a diamond structure perfectly reflected the THz wave by Bragg diffraction © 2009 IOP Publishing Ltd.
You-min Huang - One of the best experts on this subject based on the ideXlab platform.
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Development of Stereolithography Simulation Process Based on the Dynamic Finite Element Method
Key Engineering Materials, 2007Co-Authors: You-min Huang, Cho-pei JiangAbstract:In this study, a general simulation code is developed to analyze the shrinkage effect of polymerization and optimize the fabrication parameters including the scanning path, exposure time and scanning speed for the Stereolithography System. The code is based on the dynamic finite element method. Liquid element is preconstructed without curing properties till the absorption energy exceeds the critical value of dynamic stiffness matrix assembling. A unit element block is utilized with a weight coefficient for expressing a laser Gaussian energy distribution during the discretizing of the scanning path into increments. A fan blade is proposed to validate the agreement between the simulation and experimental results. The prototype is a fabrication and the surface of blade was measured by the digitizing System ATOS (Advanced TOpometric Sensor) for comparing the deformation with analysis prediction. Consequently, the simulated result closely conforms to the experimental result.
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On-line force monitoring of platform ascending rapid prototyping System
Journal of Materials Processing Technology, 2005Co-Authors: You-min Huang, Cho-pei JiangAbstract:Abstract In the processing of the bottom-exposure Stereolithography System, the curing photopolymer will connect to the resin tank as well as the upper layer. After the exposure of each layer, the forming platform has to be levered up and resin can flow into the gap between the completed layers and the resin tank. During the pulling up stage, the cured layer might not levitate together with the above layers but break and stay on the bottom of the resin tank. In order to conquer the pulling failure, a great amount of over curing is necessary to gain enough bonding force between the new exposure layer and the above layers. This over curing will cause decline of accuracy. In this paper, a super elastic intermediate material has been introduced to minimize the pulling force. The super elastic and shear strength property can help to break the vacuum between the new exposure layer and the resin tank. By the reduction of the pulling force, the amount of over curing requirement can also be reduced. Formulation of the cured forming shape and the pulling force has been proposed. The result shows that only area size is important. Hence, the pulling force can be predicted and used in on-line monitoring of the fabrication process.
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Increased accuracy by using dynamic finite element method in the constrain-surface Stereolithography System
Journal of Materials Processing Technology, 2003Co-Authors: You-min Huang, Jeng-ywen Jeng, Cho-pei JiangAbstract:Abstract The E-DARTS apparatus is a commercial rapid prototyping (RP) System that uses the constrain-surface Stereolithography (SL) technology. The advantages of the type SL System are saving resin and apparatus fees, although its accuracy needs to be increased. To find the best scanning path planning is one solution to improve the accuracy of the built part. In this paper, the diagnostic H-4 parts have been fabricated and simulated according to different path plans. The critical dimensions of the built H-4 diagnostic parts are also measured and compared with the analytical results, showing that the best path plan for building the H-4 diagnostic part is the contour-out path. In addition, it has been shown that using the skip skill in raster fill is also effective for improving the full filling of the big or long area.
Yoshinari Miyamoto - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of Three‐Dimensional Micro Photonic Crystals of Resin‐Incorporating TiO2 Particles and their Terahertz Wave Properties
Journal of the American Ceramic Society, 2007Co-Authors: Weiwu Chen, Soshu Kirihara, Yoshinari MiyamotoAbstract:Three-dimensional (3D) photonic crystals with a diamond structure made from 40 vol% TiO2–acrylate dielectric composites were formed by means of a CAD/CAM micro-Stereolithography System. The lattice constant of the diamond unit cell was 500 μm and the forming accuracy was 10 μm. The photonic band gap in the Γ–X 〈100〉 direction measured by terahertz-time-domain spectroscopy appeared at 280–360 GHz, which agreed fairly well with the band gap calculated by the plane wave expansion method.
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Smart Processing Development of Photonic Crystals and Fractals
International Journal of Applied Ceramic Technology, 2005Co-Authors: Yoshinari Miyamoto, Soshu Kirihara, Shingo Kanehira, Mitsuo Wada Takeda, Katsuya Honda, Kazuaki SakodaAbstract:A new concept of smart processing is proposed that can produce advanced materials and components by finely controlling processing energy and engineering structures. New functional components of 3D photonic crystals and fractals are demonstrated, which are constructed of dielectric ceramics and a polymer using a CAD/CAM Stereolithography System. By modifying the structure of diamond-like photonic crystals using free-form fabrication, electromagnetic waves can be controlled, opening the way for new applications in communication and sensing technology. The photonic fractal, a new material that can strongly localize electromagnetic waves without reflection and transmission, will also lead to new applications in the energy and medical fields.
Pan Huan - One of the best experts on this subject based on the ideXlab platform.
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Research on the vertical moving stage′s motion accuracy of the integral Stereolithography System
Journal of Xi'an Polytechnic University, 2010Co-Authors: Pan HuanAbstract:The basic principle of a novel integral Stereolithography System was introduced,the vertical moving stage composed by motion controlling card,drive,precision ball screw and linearslide was constructed and a test of the stage′s motion accuracy was performed.The result demonstrates that the positioning accuracy and positioning repeatability of the vertical moving stage could reach 10.9μm and 10.8μm respectively when it descends and both 7.6μm when it ascends.The test result shows that the System has developed the basic capability of mamufacturing small parts.
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research on the vertical moving stage s motion accuracy of the integral Stereolithography System
Journal of Xi'an Polytechnic University, 2010Co-Authors: Pan HuanAbstract:The basic principle of a novel integral Stereolithography System was introduced,the vertical moving stage composed by motion controlling card,drive,precision ball screw and linearslide was constructed and a test of the stage′s motion accuracy was performed.The result demonstrates that the positioning accuracy and positioning repeatability of the vertical moving stage could reach 10.9μm and 10.8μm respectively when it descends and both 7.6μm when it ascends.The test result shows that the System has developed the basic capability of mamufacturing small parts.
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Research of a Novel Integral Stereolithography System for Microstructures
2009 Second International Conference on Intelligent Computation Technology and Automation, 2009Co-Authors: Xu Guangshen, Luo Sheng, Jin Jing, Pan Huan, Hu Songqiao, Qiu RonghuaAbstract:To fabricate microstructures with rapid prototyping System, a novel integral Stereolithography (SL) System is developed. Photo-sensitive resin is solidified with image masks produced by dynamic mask generator in the novel integral SL System. The dynamic mask generator consists of high pressure mercury lamp, collimating lens, shutter, parabolic concentrator, digital micro-mirror device and its control, lens and computer. Experimental investigations were carried out to research the UV light intensity distribution in the imaging plane, and experiments are also performed to investigate the relationship of UV light intensity with position in the imaging plane and gray-scale of pattern. According to the relationship, when different portion’s gray-scale of pattern is controlled with computer, uniformity UV light intensity distribution in the imaging plane has been reached. Small size parts with intricate microstructures have been built with the integral SL System. The advantage of the novel integral SL System is that the cost of the new SL System is lower than scanning SL System, because UV lamp is used in the new SL System as light resource instead of laser in scanning SL System. In this paper, the novel SL System set-up is described in detail. Example of small size parts fabricated by the System is shown. The novel integral SL System provides a solution to the problem that has blocked the progress of SL process into high resolution with low cost.