• 정보처리학회논문지A
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• 제9A권4호
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• pp.467-478
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• 2002

유무선 인터넷의 발달로, 휴대폰, PDA, 홈패드, 스마트폰, 핸드헬드 PC 등, 다양한 형태의 자원제약을 가지는 개인용 혹은 상업용 임베디드 시스템들이 속속 등장하고 있으며, 이들로 임베딩되는 소프트웨어도, 과거 이들이 지녔던 주요 특성인 경직성(fixedness)보다도, 이제는 오히려 유연성(flexibility)을 요구하고 있다. 즉, 자원 제약 특성이 서로 다른 장치들로 유연하게 임베딩될 수 있는 특성을 요구하고 있다. 웹 상의 정보 표현을 위한 표준으로자리잡은 확장성 표기 언어인 XML을 위한 처리기는 각종 인터넷 단말에서의 자료 브라우징을 위해 필수적으로 임베딩 되어야할 소프트웨어이다. 본 논문에서는 서로 다른 기능과 자원 제약 특성을 가진 장치들에 따라 유연성 있는 임베딩을 위한 XML 처리기 구성 프레임워크인, EmXJ가 설계, 구현되며, 그 특성이 기존의 XML 처리기와 비교 분석된다.

• 마이크로전자및패키징학회지
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• 제23권2호
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• pp.19-28
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• 2016

This paper presents an overview of selected advanced measurement technologies for the mechanical properties of polymers used for flexible and stretchable electronic packaging. Over the years, a variety of flexible and stretchable electronics have been developed due to their potential applications for next generation IT industry. To achieve more flexible and wearable devices for practical applications, the usage of polymeric components has been increased significantly. Therefore, accurate measurement of mechanical properties of the polymers is necessary in order to design mechanically reliable devices. However, the measurement has been challenging due to the soft nature and thin applications of polymers. Here, we describe novel measurement technologies of mechanical properties of polymers for flexible and stretchable electronics.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.389.2-389.2
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• 2016

The flexible solid state device has been widely studied as portable and wearable device applications such as display, sensor and curved circuits. A zero-bias operation without any external power consumption is a highly-demanding feature of semiconductor devices, including optical communication, environment monitoring and digital imaging applications. Moreover, the flexibility of device would give the degree of freedom of transparent electronics. Functional and transparent abrupt p/n junction device has been realized by combining of p-type NiO and n-type ZnO metal oxide semiconductors. The use of a plastic polyethylene terephthalate (PET) film substrate spontaneously allows the flexible feature of the devices. The functional design of p-NiO/n-ZnO metal oxide device provides a high rectifying ratio of 189 to ensure the quality junction quality. This all transparent metal oxide device can be operated without external power supply. The flexible p-NiO/n-ZnO device exhibit substantial photodetection performances of quick response time of $68{\mu}s$. We may suggest an efficient design scheme of flexible and functional metal oxide-based transparent electronics.

• 한국세라믹학회지
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• 제54권6호
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• pp.518-524
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• 2017

A flexible thermoelectric device using body heat has drawn attention as a power source for wearable devices. In this study, thermoelectric thick films were fabricated by cold pressing method using p-type antimony telluride and n-type bismuth telluride powders in accordance with specific loads. Thermoelectric thick films were denser and improved the electrical and thermoelectric properties while increasing the load of the cold pressing. The thickness of the specimen can be controlled by the amount of material; specimens were approximately 700 um in thickness. Flexible thermoelectric devices were manufactured by using the thermoelectric thick films on PI (Polyimide) substrate. The process is cheap, efficient, easy and scalable. Evaluation of power generation performance and flexibility on the fabricated flexible thermoelectric device was carried out. The flexible thermoelectric device has great flexibility and good performance and can be applied to wearable electronics as a power source.

• Design & Manufacturing
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• 제13권3호
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• pp.1-11
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• 2019

Recently, studies on the development of flexible electronic devices by combining flexible materials and a conductor have been actively performed as interest in wearable devices. Especially, carbon nanotubes (CNT) or graphene coating have been used to construct a circuit to induce improvement in flexibility and rigidity. Various technologies have been developed in the surface coating of conductive materials, which are key to the manufacture of flexible electronic devices. Surface coating products with 3D coating and micro-patterns have been proposed through electrospinning, electrification, and 3D printing technologies. As a result of this advanced surface coating technology, there is a growing interest in manufacturing gradient conductive surfaces. Gradient surfaces have the advantage that they are adapted to apply a gentle change or to inspect optimum conditions in a particular region by imparting continuously changing properties. In this study, we propose a manufacturing technique to produce a continuous gradient conductive surface by combining a partial stretching of elastomer and a conductive material coating, and introduce experimental results to confirm its performance.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.314-314
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• 2013

Recently, flexibility is one of the hottest issues in the field of electronic devices. For flexible displays or solar cells, a development of transparent conductive electrodes (TCEs) with flexibility, bendability and foldability is an essential element. Hundreds of nanometers indium-tin-oxide (ITO) films have been widely used and commercialized as a transparent electrode, but their brittleness make them difficulty to apply flexible electronics. Many researchers have been studying for flexible TCEs such as a few layers of graphene sheets, carbon nanotube networks, conductive polymer films and combinations among them. Although gained flexibility, their transmittance and resistivity have not reached those of commercialized ITO films. Metal grids electrode cannot act as TCEs only, but they can be used to lower the resistance of TCEs with few losses of transmittance. However, the possibility of device shortage will be rise at the devices with metal grids because a surface flatness of TCEs may be deteriorated when metal grids are introduced using conventional methods. In our research, we have developed hybrid TCEs, which combined tens of nanometers ITO film and metal grids which are embedded in flexible substrate. They show $13{\Omega}$/${\Box}f$ sheet resistance with 94% of transmittance. Moreover, the sheet resistance was maintained up to 1 mm of bending radius. Also, we have verified that flexible organic light emitting diodes and organic solar cells with the TCEs showed similar performances compared to commercial ITO (on glass substrate) devices.

• 마이크로전자및패키징학회지
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• 제21권2호
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• pp.1-11
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• 2014

Flexible transparent conductive electrodes (TCEs) have recently attracted a great deal of attention owing to rapid advances in flexible electronic devices, such as flexible displays, flexible photovoltanics, and e-papers. As the performance and reliability of flexible electronics are critically affected by the quality of TCE films, it is imperative to develop TCE films with low resistivity and high transparency as well as high flexibility. Indium tin oxide (ITO) has been the most dominant transparent conducting material due to its high optical transparency and electrical conductivity. However, ITO is susceptible to cracking and delamination when it is bent or deformed. Therefore, various types of flexible TCEs, such as carbon nanotube, conducting polymers, graphene, metal mesh, Ag nanowires (NWs), and metal mesh have been extensively investigated. Among several options to replace ITO film, Ag NWs and metal mesh have been suggested as the promising candidate for flexible TCEs. In this paper, we focused on Ag NWs and metal mesh, and summarized the current development status of Ag NWs and metal mesh. The several critical issues such as high contact resistance and haze are discussed, and newly developed technologies to resolve these issues are also presented. In particular, the flexibility and durability of Ag NWs and metal mesh was compared with ITO electrode.

• 대한전기학회논문지:전력기술부문A
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• 제52권3호
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• pp.165-172
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• 2003

This paper presents an operation scheme to enhance the power system security by applying FACTS on Power systems. Three main generic types of FACTS devices are suggested an illustrated. Flow congestions over lines have been solved by controlling active power of series-compensated FACTS devices and low voltages at buses have been solved by controlling reactive power of shunt-compensated FACTS devices. Especially, Especially, UPFC has been applied in both line congestion and low voltages. Two kinds of indices which indicate the power system security level related to line flow and bus voltage are utilized in this paper. They have been minimized to enhance the power system security level through the iterative method and the sensitivity vector of security index is derived to determine the direction to minimum. The proposed algorithm has been tested on the IEEE 57-bus system with FACTS devices in a normal condition and a line-faulted contingency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.428-430
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• 2000

In this paper, the Flexible information display was implemented using AC powder electroluminescent device. ZnS:Cu and $BaTiO_3$ was used as a phosphor and dielectric respectively. The preparation of phosphor and dielectric layer was performed with screen printing. The implemented system of the Flexible information display was divided as following; EL display, driving circuit, software for driving. The properties of fabricated devices was measured with EL spectrum and brightness.

• Journal of Electrochemical Science and Technology
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• 제6권1호
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• pp.1-6
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• 2015

With increasing interest in flexible electronic devices and wearable appliances, flexible lithium ion batteries are the most attractive candidates for flexible energy sources. During the last decade, many different kinds of flexible batteries have been reported. Although research of flexible lithium ion batteries is in its earlier stages, we have found that developing components that satisfy performance conditions under external deformation stress is a critical key to the success of flexible energy sources. Among the major components of the lithium ion battery, electrodes, which are connected to the current collectors, are gaining the most attention owing to their rigid and brittle character. In this mini review, we discuss candidate materials for current collectors and the previous strategies implemented for flexible electrode fabrication.