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"In Hwan Lee"

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"In Hwan Lee"

Articles
Performance Characteristics of a Soft Gripper Fabricated by Additive Manufacturing Process
Woojin Jeong, Chae Young Park, Jongho Shin, In Hwan Lee
J. Korean Soc. Precis. Eng. 2023;40(10):781-785.
Published online October 1, 2023
DOI: https://doi.org/10.7736/JKSPE.023.082
Soft robots, known for their flexible and gentle movements, have gained prominence in precision tasks and handling delicate objects. Most soft grippers developed thus far have relied on molding processes using high-elasticity rubber, which requires additional molds to produce new shapes, limiting design flexibility. To address this constraint, we present a novel approach of fabricating pneumatic soft grippers using thermoplastic polyurethanes (TPU) through the Fused Filament Fabrication (FFF) technique. The FFF technique enables the creation of various gripper shapes without the need for additional molds, allowing for enhanced design freedom. The soft grippers were designed to respond to applied air pressure, enabling controlled bending actions. To evaluate their performance, we conducted quantitative measurements of the gripper’s shape deformation under different air pressure conditions. Moreover, force measurements were performed during gripper operation by varying the applied air pressure and adjusting the mounting angle. The results of this study provide valuable insights into the design and control of soft grippers fabricated using TPU and the FFF process. This approach offers promising opportunities for employing soft robots in various fields and paves the way for further advancements in robotics technology.

Citations

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  • Heated Syringe Extrusion for Soft Gripper Fabrication in Additive Manufacturing
    Kwang Yeol Yu, Woo Jin Jeong, In Hwan Lee
    International Journal of Precision Engineering and Manufacturing-Smart Technology.2025; 3(1): 59.     CrossRef
  • Multi-material additive manufacturing process design of sensor embedded soft gripper
    Kwang Yeol Yu, Hochan Kim, In Hwan Lee
    Sensors and Actuators A: Physical.2025; 386: 116322.     CrossRef
  • Application of Image Recognition Technology in Nozzle Cleaning for Material Extrusion Additive Manufacturing Processes
    Ho-Chan Kim, Yong-Hwan Bae, Hae-Yong Yun, In-Hwan Lee
    Journal of the Korean Society of Manufacturing Process Engineers.2024; 23(11): 20.     CrossRef
  • Construction of a Pneumatic Control System for Soft Gripper
    Seongyeon Kim, Kiseong Kim, Jongho Shin, Jungho Cho
    Journal of the Korean Society of Manufacturing Process Engineers.2024; 23(6): 30.     CrossRef
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Study on the Reduction of Food Fabrication Time in Additive Manufacturing Process Using Dual Nozzle
Seung Yeop Baik, Ju Ho Park, Sang In Kang, In Hwan Lee
J. Korean Soc. Precis. Eng. 2021;38(11):879-884.
Published online November 1, 2021
DOI: https://doi.org/10.7736/JKSPE.021.070
Additive manufacturing requires a relatively long time to fabricate complex three-dimensional (3D) structures or parts with more than one material. For additive manufacturing processes, production time and precision vary depending on the fabrication conditions. In this study, we developed a food additive manufacturing process of the material extrusion method type using a dual nozzle. In addition, we observed the change in the cross-sectional shape of the discharged food line according to each fabrication condition. By using a dual nozzle, the structure was fabricated under conditions of relatively high precision for the outer wall and relatively low precision for the infill, thereby shortening the production time. Through this process, it can be expected that the production time will be shortened in the food field, while the appearance will be of good quality.
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Korean Terminologies for Additive Manufacturing according to the ISO/ASTM 52900 Standard
In Hwan Lee, Ho-Chan Kim, Dong-Gyu Ahn
J. Korean Soc. Precis. Eng. 2020;37(12):929-936.
Published online December 1, 2020
DOI: https://doi.org/10.7736/JKSPE.020.093
Additive manufacturing processes have been called by a wide variety of terms since the early days of development. As these names are often mixed academically and industrially, the demand for standardization of terms has gradually increased. Accordingly, the American Society for Testing Materials (ASTM) and the International Organization for Standardization (ISO) are in the process of establishing standards for the names and definitions of important terms related to additive manufacturing. Although Korea has also begun to establish KS standards based on ISO/ASTM standards, the Korean language and definitions of important terms related to additive manufacturing as defined by ISO/ASTM have not been fully organized. Therefore, the similar terms defined in ISO/ASTM in many academic and industrial literature are called by various Korean terms. Thus, this work deals with suggestions on the Korean terminologies and standardization of important terms related to additive manufacturing based on ISO/ASTM standards. Especially, this paper deals with the Additive Manufacturing and seven sub-process classifications.

Citations

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  • Applicability Research Restoration Material of Metal PLA Sintering for Contemporary Metal Cultural Heritage
    Min Je Kim, Go Woon Bae, Sang Ok Lee
    Journal of Conservation Science.2025; 41(2): 185.     CrossRef
  • Detection Method for Island Regions in 3D Printing: A CPU-based Approach
    Young Seok Kang, Yeun Seop Kim, Seung Chae Na, Sang Jo Han
    Journal of the Korean Society for Precision Engineering.2025; 42(1): 89.     CrossRef
  • 3D Printing for Super‐Wetting Surfaces
    Yuzhe Zhang, Yujie Xue, Mingsunda Li, Yuhan Zhang
    Advanced Materials Technologies.2025;[Epub]     CrossRef
  • Trends in Materials Modeling and Computation for Metal Additive Manufacturing
    Seoyeon Jeon, Hyunjoo Choi
    journal of Korean Powder Metallurgy Institute.2024; 31(3): 213.     CrossRef
  • Application of Image Recognition Technology in Nozzle Cleaning for Material Extrusion Additive Manufacturing Processes
    Ho-Chan Kim, Yong-Hwan Bae, Hae-Yong Yun, In-Hwan Lee
    Journal of the Korean Society of Manufacturing Process Engineers.2024; 23(11): 20.     CrossRef
  • Parameter Optimization of WAAM with Pulsed GMAW for Manufacturing Propeller-Shaped Blade
    Sang-Woo Han, Hojin Yoo, Seungcheol Shin, Hansol Kim, Geonho Lee, Jongho Jeon, Sangjun Han, Jungho Cho
    International Journal of Precision Engineering and Manufacturing.2023; 24(7): 1103.     CrossRef
  • Development of novel nanocomposite radiation shielding blocks as gamma rays barrier
    Seyfi Şevik, Bünyamin Çiçek, Tuna Aydoğmuş, Hakan Güngüneş, Pelin Bayaner
    Radiation Physics and Chemistry.2023; 212: 111068.     CrossRef
  • Thermal performance analysis of aluminum, copper, and graphene nanoplatelets-doped nanocomposite heat sinks manufactured via stereolithography
    Seyfi Şevik, Bünyamin Çiçek, Özgür Özdilli, Tuna Aydoğmuş, Zelal Özer
    Applied Thermal Engineering.2023; 226: 120315.     CrossRef
  • A Study on the Effects of Edge Length and Substrate Slope on Residual Stress and Deformation Characteristics in the Vicinity of the Repaired Region for Straight Damaged Region Repair Using a DED Process
    Sung Hoon Yim, Kwang Kyu Lee, Dong-Gyu Ahn
    Journal of the Korean Society for Precision Engineering.2023; 40(7): 581.     CrossRef
  • A Study on the Development of Adaptive 5-axis Path Generation CAM S/W for High Speed Metal 3D Printer
    Sung Gun Lee, Hyun Chul Kim
    Journal of the Korean Society for Precision Engineering.2023; 40(5): 367.     CrossRef
  • Performance Characteristics of a Soft Gripper Fabricated by Additive Manufacturing Process
    Woojin Jeong, Chae Young Park, Jongho Shin, In Hwan Lee
    Journal of the Korean Society for Precision Engineering.2023; 40(10): 781.     CrossRef
  • Design for Additive Manufacturing of Agricultural Strength Assisting Exoskeleton Suit
    Kwanhyung Park, Haeyong Yun, Yongjun Cho, Hyunggil Hong, Sunho Jang, Minsu Kang, Jaehyo Kim, Hochan Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2022; 21(12): 69.     CrossRef
  • The effect of graphene-nanoplatelet and nano-teflon on mechanical properties of UV photo-resin 3D printer products
    Tunahan Hakkı Karaca, Bünyamin Çiçek, Tuna Aydoğmuş, Yavuz Sun
    Polymer-Plastics Technology and Materials.2022; 61(12): 1298.     CrossRef
  • Effects of Deposited Shape and Substrate Slope on Residual Stress and Deformation Characteristics for Repairing Old Parts via a DED Process
    Sung-Hoon Yim, Kwang-Kyu Lee, Dong-Gyu Ahn
    Journal of the Korean Society of Manufacturing Process Engineers.2022; 21(12): 77.     CrossRef
  • Analysis of Correlation between FDM Additive and Finishing Process Conditions in FDM Additive-Finishing Integrated Process for the Improved Surface Quality of FDM Prints
    Ji Won Yu, Hyung Jin Jeong, Jae Hyung Park, Dong Hun Lee
    Journal of the Korean Society for Precision Engineering.2022; 39(2): 159.     CrossRef
  • Generation Algorithm of a Novel Platform Attached Support Structure for FDM-Fused Deposition Modeling
    Ning Lv, Yunxu Li, Yujing Qiao, Ivan Giorgio
    Advances in Materials Science and Engineering.2022; 2022: 1.     CrossRef
  • Deposition Characteristics and Mechanical Properties of Stainless Steel 316L Fabricated via Directed Energy Deposition
    Seung-weon Yang, Hyub Lee, Do-Sik Shim
    Journal of the Korean Society of Manufacturing Process Engineers.2021; 20(6): 59.     CrossRef
  • Investigation of Applicability of Additive Manufacturing Processes to Appropriate Technologies for Developing Countries
    Dong-Gyu Ahn
    Academic Society for Appropriate Technology.2021; 7(2): 188.     CrossRef
  • Fabrication of Conductive Patterns by Selective Laser Sintering of Silver Nanoparticles-Photopolymer Ink
    Gil-Yong Lee, Geo-Sung Lee
    Journal of the Korean Society for Precision Engineering.2021; 38(7): 537.     CrossRef
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Additive Fabrication of Flexible Tactile Sensor using Improved Pressure Sensitive Material
In Hwan Lee, Yong Sun Choi, Ho-Chan Kim
J. Korean Soc. Precis. Eng. 2018;35(9):841-845.
Published online September 1, 2018
DOI: https://doi.org/10.7736/KSPE.2018.35.9.841
A tactile sensor is a device that collects pressure information from its environment. However, the sensors mimicking a human’s sensory system have not been sufficiently developed for practical application. It is noted that planar flexible tactile sensors have sufficient elasticity and flexibility for attachment to non-planar surfaces. But, they are subjected to an initial strain when attached to a non-planar surface. Therefore an additional calibration process is required. In this study, the fabrication process of a non-planar flexible tactile sensor is proposed, using a direct writing technology as well as an additive manufacturing technology. A curved elastic sensor body was fabricated using mold by the use of a layer-by-layer process. Moreover, the pressure sensitive material which is composed of MWCNTs and PDMA, was dispensed using a direct writing technology. The non-planar flexible tactile sensor was fabricated and tested in terms of an external pressure.

Citations

Citations to this article as recorded by  Crossref logo
  • Multi-material additive manufacturing process design of sensor embedded soft gripper
    Kwang Yeol Yu, Hochan Kim, In Hwan Lee
    Sensors and Actuators A: Physical.2025; 386: 116322.     CrossRef
  • Design and Characterization of Flexible Strain Sensors Using Pressure-Sensitive Material with Multi-walled Carbon Nanotubes and Polydimethylsiloxane
    Sanho Kim, Chae Young Park, Chien Kim, Ho-Chan Kim, In Hwan Lee
    International Journal of Precision Engineering and Manufacturing.2023; 24(12): 2361.     CrossRef
  • Study on Output Characteristics of Printed Flexible Tactile Sensors Connected to Brass Terminals
    Jindong Kim, Yonghwan Bae, Inhwan Lee, Hochan Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2020; 19(4): 65.     CrossRef
  • Optimization of Manufacturing Conditions of Pressure-Sensitive Ink Based on MWCNTs
    Sung-Chul Park, In-Hwan Lee, Yong-Hwan Bae, Ho-chan Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2019; 18(8): 1.     CrossRef
  • Improved resistance stability for tactile sensor fabrication and investigation of the dispensing parameters of a nanocomposite material
    Chaima Fekiri, Song Ho Kim, Ho-Chan Kim, In Hwan Lee
    Journal of Mechanical Science and Technology.2019; 33(12): 5631.     CrossRef
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Latest Research Trends of 3D Printing in Korea
Sung Jong Choi, Yong Hwan Bae, In Hwan Lee, Hochan Kim
J. Korean Soc. Precis. Eng. 2018;35(9):829-834.
Published online September 1, 2018
DOI: https://doi.org/10.7736/KSPE.2018.35.9.829
3D printing technology was developed in the early 1990s, and continues to grow to the present day. Globally, 3D printing technology developed as processing technology, but now progresses to various application technologies. Korea had an initial interest in overseas 3D printing technology, but the first prototype industries were limited. Recently, 3D printing technology has been attracting attention as a future technology, and the interest of people and research have been greatly increased. In Korea, it is known that many researches related to 3D printing are performed recently. However, it is true that research on the quantitative counting of specific research fields and analysis has not been sufficiently reviewed. Therefore, this paper introduces study results to understand trends of 3D printing research in Korea and to extract the mainstream fields, focusing on the articles published in Korean journals. This paper shows various indexes, such as the number of papers per year, as well as research fields and tendency of increases and decreases calculated and introduced with this topic.

Citations

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  • A Study on the Wear Phenomena of PLA and PETG Materials for 3D Printing in Non-lubricated Condition
    Yonsang Cho, Hyunseop Lee
    Journal of the Korean Society for Precision Engineering.2024; 41(2): 145.     CrossRef
  • Study on Mechanical Properties of MWCNT Reinforced Photocurable Urethane Acrylate for Additive Manufacturing
    Hyunjun Jo, Bum-Joo Lee
    Journal of the Korean Society for Precision Engineering.2024; 41(3): 199.     CrossRef
  • Mechanical Property Test Results for Additive Manufactured Specimens of Stainless Steel 316 L after Heat Treatment
    Kyungnam Jang, Seunghan Yang, Dae Seung Park
    Journal of the Korean Society for Precision Engineering.2024; 41(7): 551.     CrossRef
  • Dimensional Characteristics of Hydraulic Actuator Curve based on 3D Printing Filament Materials
    Myung-Hwi Jung, Jeong-Ri Kong, Hae-Ji Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2021; 20(1): 74.     CrossRef
  • Feasibility Study on Dimensional Standard for Material Extrusion Type 3D Printed Structures
    Sunghoon Eom, Jungjae Park, Jonghan Jin, Yong Son
    Journal of the Korean Society for Precision Engineering.2020; 37(4): 241.     CrossRef
  • Study on Output Characteristics of Printed Flexible Tactile Sensors Connected to Brass Terminals
    Jindong Kim, Yonghwan Bae, Inhwan Lee, Hochan Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2020; 19(4): 65.     CrossRef
  • Optimization of Manufacturing Conditions of Pressure-Sensitive Ink Based on MWCNTs
    Sung-Chul Park, In-Hwan Lee, Yong-Hwan Bae, Ho-chan Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2019; 18(8): 1.     CrossRef
  • Friction and Wear Characteristics of ABS-like Resin for 3D Printing Under Non-Lubricated Condition
    Young Sang Jo, Hyun Seop Lee
    Journal of the Korean Society for Precision Engineering.2019; 36(12): 1117.     CrossRef
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A Study on the Method for the Temperature Analysis of Side Wall for the Durability of Run-Flat Tires
Hyung Jin Kim, Jin Hwan Lee, Seong Rae Kim, Ki Deug Sung, Won Byoung Bae
J. Korean Soc. Precis. Eng. 2018;35(7):689-694.
Published online July 1, 2018
DOI: https://doi.org/10.7736/KSPE.2018.35.7.689
Recently, the concern for safety is increasing as customers’ interest in Run-Flat tires, which can assure their safety in case of a puncture when driving, is growing. Run-Flat tires continues to evolve with the demands of customers who want the performance of general tires such as fuel-consumption and comfort from the basic Run-Flat function in the 1st generation. Run-flat tires are designed in various ways to cope with puncture in pneumatic tires. Currently, Run-flat tires in which Runflat Inserts are inserted into sidewalls of the tires are mainly used. In this study, we would like to propose a method to predict the temperature of sidewall of a Run-flat tires while running and how it affects the durability. We predicted the temperature distribution of sidewall during the running of Run-flat tires by calculating energy loss which is from the viscoelastic characteristic of rubber through deformation analysis of tires, and verified the prediction technique by comparing with the Run-flat endurance test.
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Multi-Material Additive Manufacturing Process for 3-Dimensional Circuit Device Fabrication
Sung Taek Oh, In Hwan Lee, Ho-Chan Kim, Hae-Yong Cho
J. Korean Soc. Precis. Eng. 2018;35(3):349-354.
Published online March 1, 2018
DOI: https://doi.org/10.7736/KSPE.2018.35.3.349
Recently, various attempts have been made to apply the additive manufacturing technology directly to fabricate a product. In this regards, the industry is focusing on the multi-material additive manufacturing technology that can processes multiple materials simultaneously. This study is about the fabrication of a 3-dimensional circuit device (3DCD), based on the multimaterial additive manufacturing technology, which is combination of the material extrusion and the direct writing processes. The multi-material additive manufacturing system was developed based on the commercial multi-head FDM system. In addition, a contact type nozzle for the dispensing of the conductive material in the direct writing process is proposed. The 3-dimensional circuit device in which circuit elements are arranged on several layers was fabricated successfully, based on the presented multi-material additive manufacturing system.

Citations

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  • Application of Image Recognition Technology in Nozzle Cleaning for Material Extrusion Additive Manufacturing Processes
    Ho-Chan Kim, Yong-Hwan Bae, Hae-Yong Yun, In-Hwan Lee
    Journal of the Korean Society of Manufacturing Process Engineers.2024; 23(11): 20.     CrossRef
  • Optimization Design of Student KSAE BAJA Knuckle Using SLM 3D Printer
    Young Woo Im, Geon Taek Kim, Hyeon Sang Shin, Kang Min Kim, Bu Hyun Shin, Jong Won Lee, Jinsung Rho
    Journal of the Korean Society for Precision Engineering.2023; 40(9): 719.     CrossRef
  • Study on the Reduction of Food Fabrication Time in Additive Manufacturing Process Using Dual Nozzle
    Seung Yeop Baik, Ju Ho Park, Sang In Kang, In Hwan Lee
    Journal of the Korean Society for Precision Engineering.2021; 38(11): 879.     CrossRef
  • Optimization of Manufacturing Conditions of Pressure-Sensitive Ink Based on MWCNTs
    Sung-Chul Park, In-Hwan Lee, Yong-Hwan Bae, Ho-chan Kim
    Journal of the Korean Society of Manufacturing Process Engineers.2019; 18(8): 1.     CrossRef
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3-Dimensional Circuit Device Fabrication for Improved Design Freedom based on the Additive Manufacturing
Sung Taek Oh, Sung Hyun Jang, In Hwan Lee, Ho Chan Kim, Hae Yong Cho
J. Korean Soc. Precis. Eng. 2014;31(12):1077-1083.
Published online December 1, 2014
Multi-material Additive Manufacturing (AM) is being focused to apply for direct manufacturing of a product. In this paper, a three-dimensional circuit device (3DCD) fabrication technology based on the multi-material AM technology was proposed. In contrast with conventional two-dimensional Printed Circuit Board (PCB), circuit elements and conducting wires of 3DCD are placed in threedimensional configuration at multiple layers of the structure. Therefore, 3DCD technology can improve design freedom of an electronic product. In this paper, 3DCD technology is proposed based on AM technology. Two types of 3DCD fabrication systems were developed based on the Stereolithography and the Fused Deposition Modeling technologies. And the 3DCD samples which have same function were fabricated, successfully.
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The Cutting Tool-workpiece Interference Simulation for Worm Screw Machining by Side Milling
Min Hwan Lee, Sun-Ho Kim, Jung Hwan Ahn
J. Korean Soc. Precis. Eng. 2011;28(1):11-18.
Published online January 1, 2011
A worm screw is widely used in a geared motor unit for motion conversion from rotation to linear. For mass production of a high quality worm, the current rolling process is substituted with the milling process. Since the milling process enables the integration of all operations of worm manufacturing on a CNC(Computer Numerical Control) lathe, productivity can be remarkably improved. In this study, the tooling system for side milling on a CNC lathe to improve machinability is developed. However, the cutting tool-workpiece interference is important factors to be considered for producing high quality worms. For adaptability of various worms machining, the tool-workpiece interference simulation system based on a tool-tip trajectory model is developed. The developed simulation system is verified through several kinds of worms and experimental results.
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Mask Modeling of a 3D Non-planar Parent Material for Micro-abrasive Jet Machining
Ho Chan Kim, In Hwan Lee, Tae Jo Ko
J. Korean Soc. Precis. Eng. 2010;27(8):91-97.
Published online August 1, 2010
Micro-abrasive Jet Machining is one of the new technology which enables micro-scale machining on the surface of high brittle materials. In this technology it is very important to fabricate a mask that prevents excessive abrasives not to machine un-intend surface. Our previous work introduced the micro-stereolithography technology for the mask fabrication. And is good to not only planar material but also for non-planar materials. But the technology requires a 3 dimensional mask CAD model which is perfectly matched with the surface topology of parent material as an input. Therefore there is strong need to develop an automated modeling technology which produce adequate 3D mask CAD model in fast and simple way. This paper introduces a fast and simple mask modeling algorithm which represents geometry of models in voxel. Input of the modeling system is 2D pattern image, 3D CAD model of parent material and machining parameters for Micro-abrasive Jet Machining. And the output is CAD model of 3D mask which reflects machining parameters and geometry of the parent material. Finally the suggested algorithm is implemented as software and verified by some test cases.
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Prediction of Photopolymer Solidification for Inclined Laser Beam Exposure
Young Hyun Kim, Jong Seon Lim, Gyu Sang Yu, In Hwan Lee, Tae Jo Ko
J. Korean Soc. Precis. Eng. 2010;27(8):98-104.
Published online August 1, 2010
It has been reported that the photopolymer solidification in the stereolithogrpahy process is mainly depend on the laser exposure conditions such as laser power and scanning speed. However, these researches were focused on the vertical laser exposure onto the surface of the photopolymer. In this research, we developed a mathematical model for the photopolymer solidification under the inclined laser beam exposure. Using the developed mathematical model, the photopolymer solidifications were simulated varying inclined laser exposure conditions. Developed mathematical model was in good agreement with the experimental result. This research can be applied to improve the surface roughness in the stereolithogrpahy process.
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The Effect of Intermittent Compressive Loading to Growth of Pre-osteoblast Cells
Sung Kyu Choi, Jeong Hun Park, Seung-Jae Lee, In Hwan Lee, Sang Sun Kang
J. Korean Soc. Precis. Eng. 2010;27(2):153-159.
Published online February 1, 2010
Recently, it has been reported that mechanical stimulation takes a role in improving cell growth. Also, became generally known that skeletal system as bone or cartilage tissues take influence of compression loading. In this study, we fabricated a custom-made bioreactor and analyzed that conditions of compressive loading would influence cell growth. To compare the effect of intermittent compressive loading on cell-encapsulated agarose scaffold, we cultured preosteoblast cell (MC3T3-E1 cells) statically and dynamically. And dynamic culture conditions were produced by changing parameters such as the iteration time and interval delay time. Also, cellencapsulated agarose scaffold were subjected to 10 % dynamic compressive strain at 1㎐ frequency for 7 days. After cell culture, cell proliferation was assessed with PI stain assay for fluorescence images and flow cytometry (FACS).
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The Cutting Tool-workpiece Interference Simulation for Worm Screw Machining by Planetary Milling
Min Hwan Lee, Sun-Ho Kim, Jung Hwan Ahn
J. Korean Soc. Precis. Eng. 2009;26(12):47-54.
Published online December 1, 2009
A worm screw is widely used in a geared motor unit for motion conversion from rotation to linear. For mass production of a high quality worm, the current rolling process is substituted with the milling process. Since the milling process enables the integration of all operations of worm manufacturing on a CNC(Computer Numerical Control) lathe, productivity can be remarkably improved. In this study, the tooling system for planetary milling on a CNC lathe to improve machinability is developed. However, the cutting tool-workpiece interference is important factors to be considered for producing high quality worms. For adaptability of various worms machining, the tool-workpiece interference simulation system based on a tool-tip trajectory model is developed. The developed simulation system is verified through several kinds of worms and experimental results.
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Development of Bioreactor by Rapid Prototyping Technology
Jeong Hun Park, Seung-Jae Lee, In Hwan Lee, Dong-Woo Cho, Jong-Won Rhie
J. Korean Soc. Precis. Eng. 2009;26(3):137-143.
Published online March 1, 2009
It has been reported that mechanical stimulation takes a role in improving cell growth in skeletal system. Various research groups have been showed their own bioreactors which stimulate ceel-seed three-dimensional scaffold. In this study, we hypothesized that the various conditions of mechanical stimulation would affect cell growth and proliferation. To prove our hypothesis, we designed a custom-made bioreactor capable of applying controlled compression to cell-encapsulated scaffolds. This device consisted of a circulation system and a compression system. Each parts of the bioreactor was fabricated using the rapid prototyping technology. By using the rapid prototyping technology, we can modify and improve the bioreactor very rapidly. For dynamic cell culture, cell-encapsulated agarose gel was fabricated in 2% concentration. We performed dynamic cell culture using this agarose gel and developed bioreactor in 3 days.
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Development of Rapid Mask Fabrication Technology for Micro-abrasive Jet Machining
Seung Pyo Lee, In Hwan Lee, Tae Jo Ko, Hyun-Wook Kang, Dong-Woo Cho
J. Korean Soc. Precis. Eng. 2008;25(1):138-144.
Published online January 1, 2008
Micro-machining of a brittle material such as glass, silicon, etc., is important in micro fabrication. Particularly, micro-abrasive jet machining (μ-AJM) has become a useful technique for micro-machining of such materials. The μ-AJM process is mainly based on the erosion of a mask which protects brittle substrate against high velocity of micro-particle. Therefore, fabrication of an adequate mask is very important. Generally, for the fabrication of a mask in the μ-AJM process, a photomask based on the semi-conductor fabrication process was used. In this research a rapid mask fabrication technology has been developed for the μ-AJM. By scanning the focused UV laser beam, a micro-mask pattern was fabricated directly without photolithography process and photomask. Two kinds of mask patterns were fabricated using SU-8 and photopolymer (Watershed 11110). Using fabricated mask patterns, abrasive-jet machining of Si wafer were conducted successfully.
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