검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 15

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon fibers of polyacrylonitrile (PAN) type were coated with nickel nanoparticles using a chemical reduction method in alkaline hydrazine bath. The carbon fibers were firstly heated at 400 °C and then chemically treated in hydrochloric acid followed by nitric acid to clean, remove any foreign particles and functionalized its graphitic surfaces by introducing some functional groups. The functionalized carbon fibers were coated with nickel to produce 10 wt% Cf/Ni nanocomposites. The uncoated heat treated and the nickel coated carbon fibers were investigated by SEM, EDS, FTIR and XRD to characterize the particle size, morphology, chemical composition and the crystal structure of the investigated materials. The nickel nanoparticles were successfully deposited as homogeneous layer on the surface of the functionalized carbon fibers. Also, the deposited nickel nanoparticles have quazi-spherical shape and 128–225 nm median particle size. The untreated and the heat treated as well as the 10 wt% Cf/Ni nanocomposite particles were further reinforced in ethylene vinyl acetate (EVA) polymer separately by melt blending technique to prepare 0.5 wt% Cf-EVA polymer matrix stretchable conductive composites. The microstructures of the prepared polymer composites were investigated using optical microscope. The carbon fibers as well as the nickel coated one were homogenously distributed in the polymer matrix. The obtained samples were analyzed by TGA. The addition of the nickel coated carbon fibers to the EVA was improved the thermal stability by increasing the thermal decomposition temperature Tmax1 and Tmax2. The electrical and the mechanical properties of the obtained 10 wt% Cf/Ni nanocomposites as well as the 0.5 wt% Cf-EVA stretchable conductive composites were evaluated by measuring its thermal stability by thermogravimetric analysis (TGA), electrical resistivity by four probe method and tensile properties. The electrical resistivity of the fibers was decreased by coating with nickel and the 10 wt% Cf/Ni nanocomposites has lower resistivity than the carbon fibers itself. Also, the electrical resistivity of the neat EVA is decreased from 3.2 × 1010 to 1.4 × 104 Ω cm in case of the reinforced 0.5 wt% Cf/Ni-EVA polymer composite. However, the ultimate elongation and the Young’s modulus of the neat EVA polymer was increased by reinforcing with carbon fibers and its nickel composite.
        4,900원
        2.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A facile and efficient method was developed to prepare highly stretchable and conductive graphene conductors with wrinkled structures by the mechanical stretching and shrinking of elastomeric substrates, in which graphene inks were printed on a prestretched elastomeric substrate. Stretchable and exfoliated graphene inks were prepared by mixing graphite and Ecoflex in a shear-assisted fluid dynamics reactor. The resultant graphene conductor exhibited excellent stretchability at 150% strain and high electrical conductivity of 64 ± 1.2 S m− 1. The resistance of the conductor did not change in bent, twisted, and stretched states. The resistance did not change during 10,000 cycles of stretching/releasing, with a maximum strain of 150%. Based on the graphene conductor, a stretchable conductometric sensor with a two-electrode configuration was fabricated to measure impedance changes at different concentrations of electrolyte ions. This sensor exhibited a good and linear sensitivity curve (298.61 Ω mM− 1, R2 = 0.999) in bent and stretched states.
        4,000원
        3.
        2022.12 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 실버 파우더의 입자 크기, 즉 평균 입자 크기가 2㎛과 7㎛, 이렇게 2가지 실버 페이스트를 개발하였다. 이렇게 개 발된 실버 페이스트에 대해서 점도 및 점탄성, 경화후에 잔류용제 유무 확인을 위한 TGA측정, Strain에 따른 저항 변화 및 전극 표면 구조 변화에 대해서 검토하였다. 이러한 결과를 정리하면 Strain에 따른 저항 변화를 최소화하기 위해서는 실버 파우더의 입 자를 2㎛정도인 것이 가장 바람직함을 알 수 있었다.
        4,000원
        4.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to verify how similar the virtual fit pants are to the actual fit of stretchable pants. Data is produced using a virtual model to apply movements. The results show that in the upright position, the similarity between the appearance of the actual fit and the virtual fit is high. Results are 4.47, 4.13 and 4.33 out of 5 on the front, side, and back, respectively. The base line of the front and back, and the amount of allowance in each part were well reproduced by the model. The texture of the virtual fit was evaluated and found to be similar to the actual fabric. In terms of shape and number of wrinkles with the virtual fit pants, large wrinkles were better expressed than fine wrinkles. After applying movements to the virtual model, the front and side results were similar to the actual fit, but the back results were different. As a result of multiple comparisons, the greatest difference in similarity by movements is found in the center front line. The similarity difference was lower on the side than on the front. The only significant difference after applying movements is in the hip circumference margin. According to movements, the similarity of virtual fit is lower on the back than on the front and side, and the back also has the largest similarity differences to the movements type.
        4,800원
        5.
        2020.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        신축성 전극을 다양한 소재와과 방식을 통해 제조되고 있으며 많은 기계적 특성 분석이 연구되고 있다. 은, 구리, 금, 나노와이어 등 다양한 금속이나 CNT, graphene, 플러렌 등을 기반으로 연구되고 있으며 대부분 높은 전도성과 신축특성을 요구하는 어플리케이션에 사용되지만 고가라는 단점이 있다. 본 연구에서는 저비용 소재와 공정으로 높은 신축특성과 반복 특성을 보유한 신축성 전극을 개발하였다. 값싼 전도성 탄소 와 흑연을 혼합하여 페이스트를 개발하였고 개발된 페이스트를 메탈마스크 인쇄 공정을 통해 TPU기판 위에 인쇄하였고 120℃에서 2시간 경화를 진행하였다. 이렇게 개발된 전극을 인장 시험과 인장 반복 시험을 통해 특성을 증명하였고 향후 어플리케이션 적용 가능여부를 확인하기 위해 무릎에 임시로 고정 후 간이 시험을 진행한 결과 20회 반복하는 동안 일정한 저항 변화를 보여줬다.
        4,000원
        6.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The reduced graphene oxide/single-wall carbon nanotubes composites are coated onto the polyurethane substrate using spray coating technique to produce a stretchable and semi-transparent supercapacitor. The electrochemical properties of the stretchable and semi-transparent full device as a function of stretching cycles are characterized using electrochemical impedance spectroscopy (EIS), cyclic voltammetry and galvanostatic charge/discharge tests. The EIS and charge/discharge curves of the stretchable and semi-transparent supercapacitor exhibit good capacitive behavior even after prolonged stretching cycles up to 100. The highest capacitance value of the stretchable and semi-transparent supercapacitor (unbent) is 21.4 F g−1. The capacitance value of the stretchable and semi-transparent supercapacitor is retained 62% after 100th stretching with application of 3000th galvanostatic charge/discharge cycles.
        4,000원
        7.
        2019.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report on stretchable electrochromic films of poly(3-hexylthiophene) (P3HT) fabricated on silver nanowire (AgNW) electrodes. AgNWs electrodes are prepared on polydimethylsiloxane (PDMS) substrates using a spray coater for stretchable electrochromic applications. On top of the AgNW electrode, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is introduced to ensure a stable resistance over the electrode under broad strain range by effectively suppressing the protrusion of AgNWs from PDMS. This bilayer electrode exhibits a high performance as a stretchable substrate in terms of sheet resistance increment by a factor of 1.6, tensile strain change to 40%, and stretching cycles to 100 cycles. Furthermore, P3HT film spin-coated on the bilayer electrode shows a stable electrochromic coloration within an applied voltage, with a color contrast of 28.6%, response time of 4-5 sec, and a coloration efficiency of 91.0 cm2/C. These findings indicate that AgNWs/PEDOT:PSS bilayer on PDMS substrate electrode is highly suitable for transparent and stretchable electrochromic devices.
        4,000원
        8.
        2016.06 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 Tg가 서로 다른 폴리에스테르 바인더로 실버 페이스트를 제조하여 점도 및 점탄성를 측정하였다. 그리고 제조된 실버 페이스트를 스크린인쇄법으로 전극을 인쇄하여 folding 및 stretching test에 따른 전도성 변화 및 전극패턴의 표면형상 변화에 대해서 연구하였다. 그 결과 folding test에서는 Tg가 낮고, 높고와는 관계없이 folding횟수의 증가에 따라서 저항치가 선형적으로 증가됨을 알 수 있었다. 그러나 stretching test결과에서는 Tg에 따른 명확한 특성차이가 나타났다. 즉 신율(elongation)이 증가함에 따라서 높은 Tg을 가진 바인더로 제조된 실버 페이스트의 경우에는 40%이상에는 저항치 측정이 불가능했지만 낮은 Tg로 제조된 것은 80%까지 저항치가 측정되었다. 결론적으로 80%라는 높은 신율을 요구하는 분야에는 낮은 Tg을 가진 바인더를 사용하는 것이 바람직함을 알 수 있었다.
        4,000원
        9.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Global interest in smart-wear has risen rapidly in the 21stcentury. “Smart-wear” is one application of intelligent textiles and refers to all clothes made with intelligent textiles (or those that are a convergence). New developments represent a positive opportunity for the fashion industry to integrate new technologies to evolve. Smart-wear also includes wearable computers or digital clothing defined as “garment-integrated devices which augment the functionality of clothing, or which impart information-processing functionality to a garment”. The garment is an ideal interface medium between humans and electronic products due to interaction and technologies in the fashion industry. Smart-wear represents the future of both the textile/clothing industry and electronic industry. Smart-wear for transformable garments allow the conversion of aesthetics and functionality into multiple looks and functions that satisfy various user needs and wants. Smart-wear offers a potential paradigm shift. Precedent studies have focused on the role of transformation to understand the relationship and interaction between humans and new digital technologies (Petersen, Iversen, Krogh, & Ludvigsen, 2004). Hussein Chalayan created aa transformer dress that can twitch and reconfigure. The long Victorian dress hemline contracts into a flapper style dress. Berzowska created dresses that use shape memory alloys to move and change in continuous motions (Ariyatum & Holland, 2003).Perocich used a pneumatic approach to lift garments and change the appearance of clothes (von Radziewsky, Krüger, & Löchtefeld, 2015).Lee & Kim(2014) built a shape-changing dress which apply fabric properties and illuminance sensor to fold pleats. The idea of changing the overall appearance of clothes seems promising. Contemporary smart-wear has various functions that include sensing, actuating, powering, generating, storing, communicating, data processing and connecting. Technologies to develop digital applications can be easily controlled by smart-wear using an Arduino (Na & Cho, 2009). An embedded system for using Arduino can be worn like clothing or an accessory that is a favorable for shop window display. Shop window displays of fashion products have cultural consumption and fashioned identities that have developed into forms of art themselves and produce interesting imagery within fashion culture. In recent decades store window displays have become a unique form of advertising and are the first point of contact between the shop and the shopper (Crewe, 2015). The shop window display design might not instantly attract attention until the shopper realizes its interactive aspects. Such an interaction visually reveals a relationship between the store window and shopper's reaction. In order to connect these shop window displays with an interactive fashion design, this paper aims to illustrate how these concepts fit into the prototype. This paper develops a prototype of Wearable Shape-Changing (WSC) that deforms the fabric for pleat making on clothing for a store window dummy. Data processing is created by the motion of a shopper for the input functionality to discriminate between different shopper motions using the Microsoft Kinect sensor. A concealed Kinetic system scans every part of shopper’s joint for skeleton extraction when the shopper is outside the shop window. It is able to detect the shopper’s simple motion and simultaneously deliver information to the Arduino in the system. The prospective fashion display system needs to be devised based on a more serious technical method that utilizes information on the physical properties of fabrics to facilitate development in the store window. There has been some discussion on how fabrics could create foldable clothing items; in addition, a range folding techniques has been extended to e-textile due to useful characteristics (Perovich, Mothersill, & Farah, 2014). The experiments performed in this paper allows observers to examine basic fabric characteristics and physical properties. The behavior changes during fold deformation and the recovery process as well as identifies correlations between stiffness and recovery rate. As an experimental sample, this paper selects 2 types of fabric that have relatively stiff characteristics of a organza (one is 100% silk and the other is 100% polyester). The pleats type selects a diamond-pattern and the pleats finishing process employs a heat-setting method commonly used in the fashion industry. The results were as follows: The Silk organza has 66 weight(g/㎡) and 0.17 nominal thickness (㎜) and the Polyester organza has 39.6 weight(g/㎡) and 0.11 nominal thickness (㎜). Both silk and polyester samples have the large stiffness value in the weft direction. Tensile properties resulted in similar values in both the warp and in the weft directions. Polyester has a great thermothermos plasticity, unique resilience, providing good pleats retention and crease recovery while silk has a low wrinkle recovery. However, silk has identical recovery rate in first and second elongation deformations for diamond-pattern pleats. The diamond-pattern also has a significant correlation with the warp and bias directions. Thus, folding composition should consider the directions of the fabric according to folding technique. Based on the experiment’s results among fabric samples’ physical properties of silk were chosen for the prototype. In the prototype, the shop window displaying dummy wears a long dress, but it is designed to become shorter when the shopper lifts the arm. The mechanism by the operating design pulls the hemline in the front up to the lower thigh when the kinetic sensor detects motion. As a means of visual communications or expression of the shopper’s mood, illuminance may be attached according to the shopper’s discretion. The advantage of the WSC dress compared to a traditional static dress is that the transforming shape occurs immediately by means of interaction. Future studies, different approaches were proposed to clothing both hand and finger movements in a mobile environment. This paper focuses on a set of alliances between technology and fashion/textiles, with the WSC designed as an interface to be used for both purposes. This study represents a bridge between fashionable technologies and informative material properties. It represents a small first step from static dynamic fashion to dynamic interactive fashion.
        3,000원
        10.
        2011.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Gold have been used as an electrode materials having a good mechanical flexibility as well as electrical conductivity, however the stretchability of the gold on a flexible substrate is poor because of its small elastic modulus. To overcome this mechanical inferiority, the reinforcing gold is necessary for the stretchable electronics. Among the reinforcing materials having a large elastic modulus, carbon nanotube (CNT) is the best candidate due to its good electrical conductivity and nanoscale diameter. Therefore, similarly to ferroconcrete technology, here we demonstrated gold electrodes mechanically reinforced by inserting fabrics of CNTs into their bodies. Flexibility and stretchability of the electrodes were determined for various densities of CNT fabrics. The roles of CNTs in resisting electrical disconnection of gold electrodes from the mechanical stress were confirmed using field emission scanning electron microscope and optical microscope. The best mechanical stability was achieved at a density of CNT fabrics manufactured by 1.5 ml spraying. The concept of the mechanical reinforced metal electrode by CNT is the first trial for the high stretchable conductive materials, and can be applied as electrodes materials in various flexible and stretchable electronic devices such as transistor, diode, sensor and solar cell and so on.
        4,000원