• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.80-87
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• 2003

On this study, an End-Effector for the 300mm wafer transfer robot System is newly suggested. It is a mechanical type with $180^{\circ}$ rotating ranges and is composed of 3-point arms, two plate springs and single-axis DC motor. It is controlled by microchip for the DC motor control. To design, relationships on the gripping force and the wafer deformation is analyzed by FEM analysis. Criterion on gripping force of a suggested End-Effector is confirmed as $255 ~ 274g_f$ from experimental results. From experimented results on repeatable position accuracy, gripping force and gripping cycle times in a wafer cleaning system, we confirmed that the suggested End-Effector is well satisfied on the required performance for 300mm wafer transfer robot system.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.47-53
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• 2022

In order to conduct a study on the importance of the wrist joint, which causes a lot of pain among middle-aged people, in relation to work related to musculoskeletal disorders, the effect of stretching on grasping power was studied. In order to compare the grasping power of the wrist for middle-aged people in their 50s, the experiment was conducted by comparing before and after the wrist joint motion stretching. According to the experimental results of wrist gripping power for the control group and the experiment group on wrist gripping power, it was investigated that stretching did not change much in increasing wrist gripping power, but stretching application had an effect on wrist gripping power. In terms of preventing musculoskeletal accidents, reducing pain due to degenerative diseases, and preventing accidents, stretching seems to have an effect when approaching, so it is considered that continuous stretching before and after work is necessary. Therefore, it is suggested that stretching time secured quantitatively through safety and health education before work is necessary.

• Journal of the Korean institute of surface engineering
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• v.50 no.3
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• pp.183-191
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• 2017

In this study, surface morphology and mechanical property of TiN and DLC coated pedicle screw have been investigated by field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, vickers hardness test, axial gripping, and axial torsional gripping capacity test. From the EDS and XRD results, the composition and crystal structure of TiN and DLC coated surface were verified. The hardness value was increased by TIN and DLC coating, and the DLC coating surface has the highest value. The gripping capacity also showed higher value for TiN and DLC coated specimen than that of non-coated (Ti alloy) surface. The surface morphology of gripping tested specimen showed rougher scratched surface from Ti alloy than TiN and DLC coated layer.

• Fashion & Textile Research Journal
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• v.24 no.3
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• pp.333-345
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• 2022

This study developed and evaluated the motion control of 3D printed fingers applied to smart gloves. Four motions were programmed by assembling the module using the Arduino program: cylindrical grasping, spherical grasping, tip-to-tip pinch gripping, and three-jaw pinch gripping. Cap and re-entrant (RE) strip types were designed to model the finger. Two types of modeling were printed using filaments of thermoplastic elastomer (TPE) and thermoplastic polyurethane (TPU). The prepared samples were evaluated using three types of pens for cylidrical grasping, three types of balls for spherical grasping, and two types of cards for tip-to-tip pinch gripping and three-jaw pinch gripping. The motion control of fingers was connected using five servo motors to the number of each control board. Cylindrical and spherical grasping were moved by controlling the fingers at 180° and 150°, respectively. Pinch gripping was controlled using a tip-to-tip pinch motion controlled by the thumb at 30° and index-middle at 0° besides a three-jaw pinch motion controlled by the thumb-index finger-middle at 30°, 0°, and 0°, respectively. As a result of the functional evaluation, the TPE of 3D-printed fingers was more flexible than those of TPU. RE strip type of 3D-printed fingers was more suitable for the motion control of fingers than the 3D-printed finger.

• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.491-498
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• 1998

Transplanting process during the tissue culture of potato seedlings is costly, since the cost of highly skilled labor working in the sanitary environment takes up about 60-70% of the production cost. The objective of this study was to develop a soft gripper of a transplanting robot system for the labor-saving tissue culture. The prototype of the soft gripper was consisted of power-transmitting part finger and plant contacts. The power transmitting part transformed the rotating motion of a step motor to the reciprocating motion of the finger. Plant stems used in the test were potato seedlings cultured for six weeks. The dimensional characteristics of cultured seedlings, the compressive strengths of the stems, the extractive force from the culture medium and the gripping force of the finger were measured. A proper gripping force was found to be 0.343N at the extractive force of 0.41N when the plant contacts were made of silicon. Sixteen plants out of 70 trials were tangled with others, resulting in the success rate of 77.1%.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.643-646
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• 2003

이 논문은 작업 대상물(object)을 최소 시간으로 interception 하기 위한 방법에 대하여 기술한다. 목표는 로봇이 world coordinate system을 기준으로 x축으로 이동하는 컨베이어 라인 상에서 이동되는 작업 대상물을 intercept 하는 것이다. 컨베이어 시스템이 최소의 시간으로 작업 대상물을 intercept하기 위해서는 다음의 주요 계획이 필요하다. 첫째는 최적의 object과 end effector의 meeting point 선택, 두 번째는 첫 번째 계획이 실효를 이루기 위한 로봇의 trajectory선택이다. 두 가지의 계획 중 여기서는 두 번째 계획이 최적이라고 가정하고 첫 번째 계획법 즉, 컨베이어 시스템 로봇을 이용한 작업 대상물의 gripping 동작을 행함에 있어서 최소 시간으로 작업대상물을 gripping 하기 위한 컨베이어 시스템과 minimum time gripping 알고리즘이 제시된다.

• Tribology and Lubricants
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• v.24 no.6
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• pp.326-331
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• 2008

The contact surfaces between mold and target should be in parallel for a proper imprinting process. However, large size of contacting area makes it difficult for both mating surfaces (mold and target planes) to be in all uniform contact with the expected precision level in terms of thickness and position. This is caused by the waviness of mold and target although it is very small relative to the area scale. The gripping force for both mold and target by the vacuum chuck is other major effect to interrupt the uniform contact, which must be avoided in imprinting mechanism. In this study, the cause of non-conformal contact mechanism between mold and target is investigated with the consideration of deformation due to the vacuum gripping for the size $470{\times}370\;mm^2$ LCD panel.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.55-60
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• 2022

The effect of motion taping on the grasping power of the wrist is investigated and here Based on the data obtained from the This study was conducted to provide a theoretical background for the study. Motion taping was performed on the wrist for middle-aged people between 50s and 60s, and the change in wrist gripping power through an electronic dynamometer was tested. According to the wrist grip test results, it was investigated that the application of motion taping has a great effect on the gripping power of the wrist. It is hoped that motion taping will be a tool to reduce musculoskeletal industrial accidents, and it will be helpful to improve the quality of life of workers by reducing the labor intensity or softening the wrist through motion taping.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.282-287
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• 2022

High shear adhesion on wet and rough surfaces and tactile feedback of gripping forces are highly important for realizing robotic gripper systems. Here, we propose a bioinspired robotic gripper with highly shear adhesion and sensitive pressure sensor for tactile feedback systems. To achieve them, we fabricated multi-walled carbon nanotube sensing layer on a thin polymeric adhesive layer of polydimethylsiloxane. With densely hexagonal-packed microstructures, the pressure sensor achieved 9 times the sensing property of a sensor without microstructures. We then assembled hexagonal microstructures inspired by the toe pads of a tree frog, giving strong shear adhesion under both dry and wet surfaces such as silicon (42 kPa for dry and ~30 kPa for underwater conditions) without chemical-residues after detachment. Our robotic gripper can prevent damage to weak or smooth surfaces that can be damaged at low pressure through pressure signal feedback suggesting a variety of robotic applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.246-250
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• 2003

In this study, two new types of micro-grippers in which micro-fingers are actuated by piezoelectric multi-layer benders and stacks are introduced for the manipulation of micrometer-sized objects. First, we constructed a 3-chopstick-mechanism tungsten gripper, which is composed of three chopsticks: two are designed to grip micro-objects, and tile third is used to help grasp and release the objects through overcoming especially electrostatic force among some surface effects including electrostatic, van der Waals forces and surface tension. Second, a 2-chopstick-mechanism silicon micro-gripper that uses an integrated force sensor to control the gripping force was developed. The micro-gripper is composed of a piezoelectric multilayer bender for actuating the gripper fingers, silicon fingertips fabricated by use of silicon-based micromachining, and supplementary supports. The micro-gripper is referred to as a hybrid-type micro-gripper because it is composed of two main components; micro-fingertips fabricated using micromachining technology to integrate a very sensitive force sensor for measuring the gripping force, and piezoelectric gripper finger actuators that are capable of large gripping forces and moving strokes. The gripping force signal was found to have a sensitivity of 667 N/V. To the design of each of components of both of the grippers. a systematic design approach was applied, which made it possible to establish the functional requirements and design parameters of the micro-grippers. The micro-grippers were installed on a manual manipulator to assess its performance in tasks such as moving micro-objects from one position to a desired position. The experiment showed that the micro-grippers function effectively.