• 한국공간구조학회논문집
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• 제16권1호
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• pp.35-42
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• 2016

Until recently, almost all ETFE film structures that have been erected is the cushion type because there are problems at lower allowable strength under elastic range and viscosity behaviour such as creep and relaxation of ETFE films under long-term stresses. But the number of tension type structures is currently increasing. This paper proposes the stretch fabrication of ETFE film to verify the applicability of ETFE films to tensile membrane structures. First of all, to investigate the possibility of application on tensile membrane structures, the stretch fabrication test is carried out, and it is verified that it is possible to increase the yield strength of the film membrane structures. After simulating the experiment also carries out an analytical investigation, and the effectiveness of the elasto-plastic analysis considering the viscous behavior of the film is investigated. Finally, post-aging tension measurement is conducted at the experimental facilities, and the viscosity behavior resulting from relaxation is investigated with respect to tensile membrane structures.

• 한국공간구조학회논문집
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• 제14권3호
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• pp.85-92
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• 2014

Most of the structural forms in which ETFE film is used are the cushion(pneumatic membrane structures) and tension type(tensile membrane structures), which have been generally accepted to be the most efficient forms. Tensile membrane structures are pulled outward from the exterior to introduce initial stress. And such structures offer the advantage of a natural shape formed by tensile stress and eliminate the need for blast air. Recently, the number of tension type structures is increasing. However, there are problems of creep and relaxation of ETFE films under long-term stresses. In this paper, the stretch fabrication method is proposed for stretching the film into the plastic region during initial tensioning as a way to increase its strength. And its effectiveness is confirmed by investigating experimental and analytical test using ETFE films.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1394-1396
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• 1994

Polyimide thin films were fabricated an using vapor deposition polymerization apportus, and their FT-IR and TGA characteristics were investigated. The peaks of $720cm^{-1}$ and $1380cm^{-1}$ show C=O stretch mode and C-N stretch mode, and that of the cured polyimide at $350^{\circ}C$ were sturated. $T_d$(Depolymerization temperature) was showed at $405^{\circ}C$ from research of thermal resistivity characteristics by TGA It was possible to fabrication of polyimide thin film by VDPM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1639-1641
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• 1996

Polyirnide thin films were fabricated an using vapor deposition polymerization apparatus, and their FT-IR and TGA characteristics were investigated. The peaks of $720cm^{-1}$ and $1380cm^{-1}$ show C=O stretch mode and C-N stretch mode, and that of the cured polyimide at $300^{\circ}C$ were saturated. TGI(Thormogravi metric index) was showed at $459^{\circ}C$ from reaserch of thermal resistivity characteristics by TGA.

• 한국운동역학회지
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• 제22권4호
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• pp.421-428
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• 2012

The purpose of this study was to verify the effects of developed assisting wear which maximize trunk(back) muscle's stretch-shortening effect during backswing and downswing for increasing golf ball carrying distance. Design and fabrication of assistive wear were performed based on the results of analyzed data of trunk EMG activity from the golf drive swings of elite professional male golfers during back swing and downswing phases. After the prototype of wear was produced, surface EMG and Flight scope tests were conducted to verify the effectiveness of the wear for increasing distance to the professional golfers. Results indicated that wearing trial showed significant longer carry distance than the non-wearing trial(p<.001). The carry distance of wearing trial showed an average 229 m compared to the non-wearing trial, the average 225 m. The swing with wearing also produced significantly faster ball speed than the trial without wearing(p<.05). Average 245 Km/h and 244 Km/h were produced for the swing with and without wearing trails, respectively. EMG results also indicated that the muscle activity of left psoas was significantly increased for wearing trial during downswing and near the impact. Thus, this may affect positively to increase club head speed. The activity of the left latissimus dorsi was dramatically increased during the final stage of swing. This generates elongation effect for longer follow-through and increased impulse between club and ball so eventually valid assistance to increase carry distance. Therefore, the developed assisting wear was proved to be effective tool for increasing golf ball carry distance with maximizing trunk(back) muscle's stretch-shortening effect during backswing and downswing.

• 한국염색가공학회지
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• 제27권2호
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• pp.126-131
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• 2015

Silica-polyurethane hybrid breathable films were prepared and their breathabilities were assessed. Appropriately aggregated silica was prepared through sol-gel reaction of water glass and its particle size ranged 360~500nm. The polyurethane dispersion was prepared by the reaction of isophorone diisocyanate(IPDI) as diisocyanate and polytetramethylene glycol(PTMG) and dimethylol propionic acid(DMPA) as polyol, particle size ranging 30~120nm. The reaction between isocyanate and hydroxyl group to form urethane bonding was checked by the intensity of the stretch peak of isocyanate at $2270cm^{-1}$ in the FT-IR. The silica was incorporated into polyurethane dispersion and casted into film. It was shown that the incorporated silica(1~5wt.%) increased water vapour permeability of the films by 30~100%, and decreased the hydrostatic pressure by 10~40%. From the results, it could be concluded that the appropriate hybridization of silica can increase the breathability of polyurethane dispersion film, while minimizing the loss of hydrostatic pressure.

• 한국진공학회지
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• 제20권4호
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• pp.276-279
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• 2011

약밀려남/잡아당김/급냉각의 연속적인 압출 공정을 이용하여 대면적 불화 고분자 막을 제작하였다. 제안한 방법으로 형성된 불화 고분자 박막은 $C_i=2.9\;nF/cm^2$의 전기용량밀도가 측정되었고, 1kHz에서의 ${\varepsilon}_r$=56의 높은 유전상수를 나타내었다. $1.5406{\AA}$의 파장에서 Bruker AXS X-ray 회절분석기를 통해 $18.0^{\circ}$에서 최고점을 나타내어 전기변형 성능에 적합한 ${\beta}$ 상태를 확인하였다. 본 연구는 넓은 면적의 인공근육에 응용 가능한 전기변형 불화고분자막의 새로운 박막 형성 기술로 이용될 수 있다.

• 감성과학
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• 제24권2호
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• pp.49-56
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• 2021

본 연구의 목적은 생체 신호 측정 압력 및 인장 직물 센서의 전극을 자수 공정을 이용하여 제작할 때 전도사의 필요 물성을 파악하는 것이다. 스마트 웨어러블 제품의 전극을 전도사를 이용한 자수 공정을 통해 전극 및 회로 등을 제작하면 불필요한 재료 손실이 없고 복잡한 전극 모양이나 회로 디자인을 컴퓨터 자수기를 이용하여 추가 공정 없이 제작할 수 있다. 하지만 보통의 전도사는 자수 공정 내의 부하를 못 이기고 사절 현상이 발생하기에 본 연구에서는 silver coated multifilament yarn 3종류의 기계적 물성인 S-S curve, 두께, 꼬임 구조 등을 분석하고 동시에 자수기의 실의 부하를 측정하여 자수 공정 내 전도사의 필요 물성을 분석하였다. 실제 샘플 제작에서 S-S curve의 측정 결과가 가장 낮은 silver coated polyamide/polyester가 아닌 silver coated multifilament의 사절이 발생하였으며 그 차이는 실의 꼬임 구조와 사절이 일어난 부분을 관찰한 결과 수직으로 반복적인 부하가 일어나는 자수 공정에서 꼬임이 풀리면서 사절이 일어나는 것을 알 수 있었다. 추가적으로 압저항 압력/인장 센서를 제작하여 생체 신호 측정용 지표인 gauge factor를 측정하였으며 스마트 웨어러블 제품의 대량 생산화에 중요한 부분인 자수 전극 제작으로의 적용 가능성을 확인하였다.

• 한국의류산업학회지
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• 제24권6호
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• pp.694-706
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• 2022

This study focusses on the development of a motion-sensing smart leggings prototype with the help of a module that monitors motion using a fiber-type stretch sensor. Additionally, it acquires data on Electrocardiogram (ECG), respiration, and body temperature signals, for the development of smart clothing used in online exercise coaching and customized healthcare systems. The research process was conducted in the following order: 1) Fabrication of a fiber-type elastic strain sensor for motion monitoring, 2) Positioning and attaching the sensor, 3) Pattern development and three-dimensional (3D) design, 4) Prototyping 5) Wearability test, and 6) Expert evaluation. The 3D design method was used to develop an aesthetic design, and for sensing accurate signal acquisition functions, wearability tests, and expert evaluation. As a result, first, the selection or manufacturing of an appropriate sensor for the function is of utmost importance. Second, the selection and attachment method of a location that can maximize the function of the sensor without interfering with any activity should be studied. Third, the signal line selection and connection method should be considered, and fourth, the aesthetic design should be reflected along with functional verification. In addition, the selection of an appropriate material is important, and tests for washability and durability must be made. This study presented a manufacturing method to improve the functionality and design of smart clothing, through the process of developing a prototype of motion-sensing smart leggings.