• 대한기계학회논문집B
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• 제36권5호
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• pp.539-543
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• 2012

셀룰로오스 EAPap 작동기는 생체 모방형 작동기의 하나로 생체적합하고 가볍고 비교적 낮은 전압에서도 큰 변위를 발생시킨다는 장점을 가지고 있다. 셀룰로오스를 재생하면서 셀룰로오스 파이버를 배열함으로써 압전 종이를 만들었다. 한편 셀룰로오스에 탄소나노튜브, 산화금속 나노분말, 전도성 고분자, 이온성 유체등을 물리적, 화학적으로 결합시켜 다양한 하이브리드 나노복합재를 만들었다. 본 논문에서는 셀룰로오스 EAPap 의 제조공정 및 이를 응용한 바이오센서, 화학센서, 유연트랜지스터, 그리고 작동기의 응용 디바이스에 대해 소개한다. 또한 셀룰로오스 EAPap 을 무선으로 구동하는 기술에 대해 소개한다. 이는 생체모방로봇, 정찰 등에 활용될 수 있다.

• Corrosion Science and Technology
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• 제14권5호
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• pp.207-212
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• 2015

The purpose of this research was to synthesize fluorine modified waterborne polyurethane dispersion (F-WPU) by soap-free (internal emulsifier) emulsion polymerization techniques, to prepare coating solution based on fluorine modified waterborne polyurethane dispersion (F-WPU) and to compare the chemical and thermo-mechanical properties on the electrogalvanized steel sheet. Environmentally friendly F-WPU was prepared with a fluorinated polyol containing 60 wt% of fluorine. There are various ways of combining a wide variety of fluorinated polyols and diisocyanate to exhibit novel properties of waterborne polyurethane dispersion. Components of coating solution were largely divided into 4 kinds i.e., F-WPU, acrylic emulsion, silane coupling agent, and colloidal silicate. F-WPU coating solution on the electro-galvanized steel sheet showed excellent properties of corrosion resistance, alkali resistance and heat resistance, as compared to other coating solutions using a general waterborne resin. The F-WPU coating solution's reliable effects are possibly due to the fluorine atoms incorporated even in a small amount of F-WPU.

• Smart Structures and Systems
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• 제13권1호
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• pp.1-24
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• 2014

The present study deals with two dimensional electro-elastic analysis of a functionally graded piezoelectric (FGP) cylinder under internal pressure. Energy method and first order shear deformation theory (FSDT) are employed for this purpose. All mechanical and electrical properties except Poisson ratio are considered as a power function along the radial direction. The cylinder is subjected to uniform internal pressure. By supposing two dimensional displacement and electric potential fields along the radial and axial direction, the governing differential equations can be derived in terms of unknown electrical and mechanical functions. Homogeneous solution can be obtained by imposing the appropriate mechanical and electrical boundary conditions. This proposed solution has capability to solve the cylinder structure with arbitrary boundary conditions. The previous solutions have been proposed for the problem with simple boundary conditions (simply supported cylinder) by using the routine functions such as trigonometric functions. The axial distribution of the axial displacement, radial displacement and electric potential of the cylinder can be presented as the important results of this paper for various non homogeneous indexes. This paper evaluates the effect of a local support on the distribution of mechanical and electrical components. This investigation indicates that a support has important influence on the distribution of mechanical and electrical components rather than a cylinder with ignoring the effect of the supports. Obtained results using present method at regions that are adequate far from two ends of the cylinder can be compared with previous results (plane elasticity and one dimensional first order shear deformation theories).

• Journal of Mechanical Science and Technology
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• 제18권10호
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• pp.1730-1737
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• 2004

The BI (Ball Indentation) method has the potential to assess the mechanical properties and to replace conventional fracture tests. In this study, the effect of aging on mechanical behavior of 1Cr-1Mo-0.25V steels procured by isothermal aging heat-treatment at four different aging times in the range of 0～1820 hours at 630$^{\circ}C$, were investigated using BI system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.253-253
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• 2008

Recently, high performance microelectronic devices are designed in multi-layer structure in order to make dense wiring of metal conductors in compact size. For making dense wiring of metal conductors, we investigated CTE and peel strength of dielectric materials for next generation PCB. It is an object of this research to develop an epoxy resin composition for an interlayer insulating material exhibiting low CTE and high peel strengnth and making an insulating layer thinner.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.591-596
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• 2006

Lead zirconate titanate(PZT) thin films have been attracting worldwide interests in exploring their potential properties [1-3] or the origins [4-6] of their excellent dielectic, ferroelectric and piezoelectric properties near the morphotropic phase boundary (MPB). PZT thin films are expected to apply to the memory devices, micro electro mechanical systems (MEMS), and display because of their superior ferroelectric, pyroelectric, piezoelectric and electron emission properties. In this study, high- performance piezoelectric PZT thin films for actuated mirror array and optical scanner were developed by controlling the several factors, such as molecular-designed precursor, seeding layer and the residual stress in films, by a chemical solution deposition (CSD).

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.531-533
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• 2013

본 논문에서 연구하고자 하는 IPMC(Ionic exchange Polymer Metal Composite)는 술폰산 이온기와 플루오르화 탄소의 결합으로 이루어진 Nafion 필름을 사용한 소재로 전기 활성 고분자(Electro Active Polymer) 특성과 물의 유무 및 양이온에 크게 영향을 받는 특성을 지닌다. 즉, 전기 에너지를 기계적 에너지로 활용 하거나, 기계 에너지를 전기 에너지로 활용 할 수 있으며, 물과 물속의 양이온에 따라 그 특성도 크게 달라진다. 이러한 IPMC의 전기적 특성을 연구하기 위하여 모의실험 장치를 구성하였다. 이 모의 실험 장치에는 MCU 와 Stepper Motor를 사용 하여 해류의 기계적 움직임을 구현 하도록 하여 움직임에 따른 전기적 특성 분석을 하도록 설계 하였다. 본 연구에서는 IPMC와 모의실험 장치를 구성 하여 해류 에너지의 효율 적인 사용을 위하여 IPMC의 면적, 주파수, 염분의 농도, Bending 각도에 따른 전기적 분석 연구 방법을 통해 IPMC의 효율적인 사용 방법을 제안하고자 한다.

• 한국초전도ㆍ저온공학회논문지
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• 제9권4호
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• pp.11-15
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• 2007

In practical applications of HTS tapes for electric devices such as coils and power cables, the jointing of HTS tapes is inevitable even though long length tapes have recently been achieved. The critical current, $I_c$, degradation behaviors with tensile and bending deformations were investigated in commercially available YBCO coated conductor tapes. When the V-I relationship was measured at the jointed section of the lap-jointed YBCO CC tapes, the resistance at the joint decreased with increasing joint length. The critical load for 95% $I_c$ retention were determined for the IBAD and RABiTS YBCO tapes and they were 175 and 355N, respectively. Fracture occurred at the unjointed part which represents strong copper lamination and solder jointing. The electro-mechanical properties of lap-jointed CC tapes depended on the properties of single tapes. The V-I behavior under bending strain was similar with the tensile case.

• 한국정밀공학회지
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• 제20권2호
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• pp.94-103
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• 2003

In case of environment requiring safety such as human body and requiring flexible shape, a conventional mechanical actuator system does not satisfy requirements. Therefore, in order to solve these problems. a research of various smart material such as EAP (Electro Active Polymer), EAC (Electro Active Ceramic) and SMA (Shape Memory Alloy) is in progress. Recently, the highest preferring material among various smart material is EP (Electrostictive Polymer), because it has very fast response time, powerful force and large displacement. The previous researches have been studied properties of polymer and simple control, but present researches are studied a polymer actuator. An EP (Electostrictive Polymer) actuator has properties which change variably ils shape and environmental condition. Therefore, in order to coincide with a user's purpose, it is important not only to decide a shape of actuator and mechanical design but also to investigate a efficient controller. In this paper, we constructed the control logic with an adaptive fuzzy algorithm which depends on the physical properties of EP that has a dielectric constant depending on time. It caused for a sub-actuator to operate at the same time that a sub-actuator system operation increase with a functional improvement and control efficiency improvement in each actuator, hence it becomes very important to manage it effectively and to control the sub-system which Is operated effectively. There is a limitation on the management of Main-host system which has multiple sub-system, hence it brings out the Multi-Vehicle Control process that disperse the task efficiently. Controlling the multi-dispersion system efficiently, it needs the research of Main-host system's scheduling, data interchange between sub-actuators, data interchange between Main-host system and sub-actuator system, and data communication process. Therefore in this papers, we compared the fuzzy controller with the adaptive fuzzy controller. also, we applied the scheduling method for efficient multi-control in EP Actuator and the algorithm with interchanging data, protocol design.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.161-164
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• 2001

In this paper, we investigated the dielectric and piezoelectric properties of Pb(Sb, Nb)O$_3$-Pb(Zr, Ti)O$_3$ ceramic(PSN) for piezoelectric transformer and actuator etc. Effect of MnO$_2$ addition on the PSN ceramic was investigated. Anisotropic properties of electromechanical coupling factor and piezoelectric properties proved to be varied with amount of MnO$_2$ impurity and sintering temperature. The electromechanical coupling factor k$_{p}$ of 0.38 and the mechanical quality factor Q$_{m}$ of 1944 were obtained from the specimen with 0.4 wt% MnO$_2$ sintered at 115$0^{\circ}C$ addition. Experimental results indicated that the PSN ceramic with MnO$_2$ impurity can be effectively used for piezoelectric transformer and actuator.tor.