• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3298-3300
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• 1999

In this paper, a $10{\times}10$ micro SLM array for phase and amplitude modulation of incident light is designed and fabricated using surface micromachining technology. Hidden spring structure is used in order to maximize the fill-factor and minimize diffraction effect at the support posts. Static and dynamic characteristics of designed micro SLM are simulated with ABAQUS and measured with optical measurement system using He-Ne laser and PSD(position sensitive devise).

• 로봇학회논문지
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• 제3권3호
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• pp.203-211
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• 2008

This work proposes structure of spring backbone micro endoscope. For effective surgery in narrow and limited space, many manipulators are developing that different to existed structure. This device can move like elephant nose or snake unlike the existing robots. For this motion, a mechanism that uses spring backbone and wires has been developed. The new type endoscope that has Z axis motion for spring structure, therefore it has 3 degree of freedom, two rotations and one linear motion. And new kinematics for backbone structure is proposed using simple geographic analysis. The Jacobian and stiffness modeling are also derived. Exact actuator sizing is determined using stiffness model. Finally, the proposed kinematics are verified by simulation and experiments.

• 한국기계가공학회지
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• 제6권2호
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• pp.22-27
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• 2007

In this study, the two methods of stiffness measurement(Spring constant) of cantilever were proposed for quantitative measurement in Atomic Force Microscopy(AFM). As the 1st method for the measurement of stiffness, the probe method, which is used in the measurement of the semiconductor mechanical and electrical properties, was applied to the measurement of the cantilever. Experiments by the probe method were performed finding the resistance value of cantilever. As the results, the resistance was measured differently along with the dimension and the thickness of cantilever that determined the stiffness(spring constant) of the lever. As the 2nd method, the vibration characteristics(Dunkerley expression) is used to obtain the stiffness of the complex structure which is combined by AFM cantilever and the standard cantilever. We measured the resonant frequency from the complex structure using the micro stages and stereo microscope. As the results, we confirmed that the vibration characteristics(Dunkerley expression) is effected the micro complex structure of AFM cantilever.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.71-71
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• 2012

Memory 반도체 Test공정에서 사용되는 Probe Card의 Probing Area가 넓어지면서 종래에 사용되던 Cantilever제품의 사용이 불가능하게 되고, MEMS공정을 사용한 새로운 형태의 Advanced제품이 시장에 출현을 하였다. MEMS형의 제품은 다수의 Micro Spring을 MLC(Multi Layer Ceramic)위에 MEMS 공정을 사용하여 생성하는 방식으로서 MLC는 좁은 지역에 다수의 Pin을 생성 할 수 있는 공간을 만들어 주며, 또 다른 이유는 전기적 특성인 임피던스를 맞추고 다수의 Pin의 압력에 의하여 생기는 하중을 Ceramic기판으로 지탱하기 위한 목적도 있다. 이에 MLC와 같은 전기적 특성을 임피던스를 맞춘 RF-CPCB를 사용하여 작은 면적에 다수의 Pin접합이 가능한 방법을 마련한 후, 이 RF-PCB를 부착하여 Pin의 하중을 받는 Wafer와 유사한 열팽창을 갖는 Substrate를 사용하여 MLC를 대체하여 다양한 온도 조건에서 사용이 가능하며, 복잡하고 공정비가 많이 드는 MEMS 공정에 의한 일괄 Micro Spring 생성 공정을 전주 도금 또는 2D방식의 도금 Pin으로 대체하였으며, Probe Card의 중요한 물리적 특성인 Pin들의 정렬도를 마련하기 위해 Photo Process를 사용한 Wafer로 만든 Wafer Pin Array Frame을 사용하여 2D 제작 Pin을 일괄 또는 부분 접합이 가능한 방법으로 Probe Array Head를 제작하여 이들을 부착하여 Probe Array Head를 이전의 MEMS공정 방법에 비해 쉽고 빠르게 만들어 probe Card를 제작 할 수 있게 되었다.

• 대한기계학회논문집A
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• 제27권1호
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• pp.183-193
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• 2003

Micro-weighing device by using null balance method is being essential part in fields of high-technology industries such as precision semiconductor industry, precision chemistry, biotechnology and genetics etc. Also, requirements for high resolution and for large measurement range increase more and more. The performance of the micro-weighing device can be determined by the mechanism design and analysis. The analytical design method has been proposed for the performance improvement such as resolution, measurement range and fast response. The 2-stage displacement amplification is designed to overcome the limit of conventional force transmitting lever. The parallel spring is designed for the measurement result independent of the input force position variation. Also, the natural frequency of mechanism is analyzed for the fast response. After each analysis, optimal design has been carried out. To verify the analysis and design result, characteristics experiments had been carried out after construction. Finally, the system had been controlled.

• 대한치과교정학회지
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• 제49권2호
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• pp.106-115
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• 2019

Objective: This study aimed to evaluate the effects of force loading on root damage caused by contact with temporary anchorage devices (TADs) during orthodontic treatment and to examine the repair process 4, 8, and 12 weeks after TAD contact by micro-computed tomography (CT). Methods: We enrolled 42 volunteers who required bilateral upper first premolar extractions. The experimental study design was as follows. For both first premolars, cantilever springs were placed, and then TADs were immediately inserted between the premolars of all volunteers. According to the removal order of the appliances, the participants were divided into the TAD group (Group T: n = 21, only TAD removal) and the spring group (Group S: n = 21, only spring removal). A splitmouth design was adopted in both groups as follows. For each volunteer, the left premolars were extracted 4, 8, or 12 weeks after TAD-root contact. The right premolars were extracted immediately after contact in both groups (Groups T-C and S-C) and used as positive controls. Resorption volumes and numbers of craters were determined by micro-CT. Results: The numbers of resorption craters were higher in Group T than in Group S at 8 and 12 weeks (p < 0.01). Crater volumes were higher in Group T than in Group S at 4 and 12 weeks (p < 0.01, both). Conclusions: Root injury was not completely repaired 12 weeks after root-TAD contact, even when the TADs were removed in cases of continuous force application.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권4호
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• pp.269-274
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• 1999

A bending actuator using zigzag type shape memory alloy springs has been fabricated and characterized. The fabricated millimeter-sized actuator has outer diameter of 3.0mm and inner diameter of 2.0mm. The zigzag type spring is more suitable for thin wall type actuator because the zigzag type spring has a planar structure comparing with the coil type spring which has a three-dimensional structure. The measured characteristics of the fabricated bending actuator show the possibility of practical application to micro active bending catheters.

• 한국공작기계학회논문집
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• 제10권5호
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• pp.31-38
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• 2001

This paper deals with the micro turning property of setting angle using diamond tool. The bed of the system has used the granite which has the thermal and vibrational characteristics superior to the cast iron bed for the common machine tool. To minimize the inner and outer vibration of the fuming system, an air pad system was manufactured and tested. The aero-static spindle system which has the excellent rotation accuracy was designed and manufactured. As a result of the micro-cutting test on aluminum alloy, tool setting angel have effected on surface roughness. From the results, the micro-cutting conditions hope to provide the useful actual data using in industrial fields.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2512-2514
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• 1998

The bending actuator using zigzag type shape memory alloy springs has been fabricated and characterized. The small sized actuator with outer diameter of 3.0mm and inner diameter of 2.0mm could be implemented because zigzag type spring has advantages for thin wall type actuator over the coil type spring. The measured characteristics of the fabricated bending actuator show the possibility of practical application to micro active bending catheter.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.922-927
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• 2004

The bending moment and settlement of the slab track can be reduced by the installation of small numbers of micro piles beneath the track. This paper presents the effect of micro pile installation on the reduction of bending moment and settlement of slab track, estimated by a numerical method. The slab track is modeled as a plate based on the Mindlin's plate theory, and soil and piles are modeled as Winkler and coupled springs, respectively. The stiffness of piles is obtained by the approximate analytical method proposed by Randolph and Wroth. and the modulus of subgrade reaction is adopted to evaluate Winkler spring constant. From the analysis results, the effect of the micro pile installation is significant to considerably reduce the settlement of slab track. However, for the proper reduction of bending moments in a slab track, the pile arrangement should be reasonably taken into account to prevent the stress concentration at pile location.