• 한국정보통신학회논문지
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• 제17권3호
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• pp.533-539
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• 2013

최근 의료 및 생체공학 분야의 액추에이터(actuator)와 센서 및 연료전지로 활용할 수 있는 새로운 재료인 IPMC(Ionic Polymer Metal Composite)에 대한 관심이 높아지고 있다. 이러한 IPMC의 특징은 센서(sensor)와 액추에이터(actuator)의 성질을 동시에 가지는 있는 특이한 성질을 가진 복합재료로서 IPMC에 전압을 가하면 움직임이 생기며, IPMC에 움직임이 발생하면 IPMC 내부에 전압이 충전되는 성질이 있어 모션 센서나 힘 센서로도 활용할 수 있다. 본 논문에서는 이러한 IPMC에 대한 몇 가지 특성을 파악하고 IT 기술인 스마트폰의 연계하여 원격지에서 IPMC의 동작을 제어할 수 있도록 시스템을 구성하였다. 또한, 스마트폰을 기반으로 하여 영상정보를 전송하여 모니터링 하도록 하였다. IPMC의 동작제어는 스마트폰의 블루투스를 이용하여 동작명령을 전송하도록 시스템을 구현하였다. 본 논문의 실험 및 구현으로부터 IPMC 물성에 대한 정확한 분석은 부족하지만 향후 IPMC의 활용에 있어서 IT 기술과의 융합을 통하여 센서, 액추에이터, 연료전지 등과 같은 분야에 적극 활용할 수 있음을 확인할 수 있었다.

• 한국재료학회지
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• 제18권11호
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• pp.617-622
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• 2008

In this study, the additivity factors of compositions to density and glass transition point ($T_g$) in a $xLi_2O-(1-x)[(1-y)TeO_2-yZnO]$ (0$T_g$ was discussed. As a method for predicting the relation between glass structure and ionic conductivity, density was measured by the Archimedes method. The glass transition point was analyzed to predict the relation between ionic conductivity and the bonding energy between alkali ions and non-bridge oxygen (NBO). The relation equations showing the additivity factor of each composition to the two properties are as follows: Density(g/$cm^3$) = $2.441x_1\;＋\;5.559x_2\;＋\;4.863x_3\;T_g(^{\circ}C)$ = $319x_1\;＋\;247x_2\;＋\;609x_3\;－\;1950x_1x_3$ ($x_1$ : fraction of $Li_2O$, $x_2$ : fraction of $TeO_2$, $x_3$ : fraction of ZnO) The density decreased as $Li_2O$ content increased. This was attributed to change of the $TeO_2$ structure. From this structural result, the electric conductivity of the glass samples was predicted following the ionic conduction mechanism. Finally, it is expected that electric conductivity will increase as the activation energy for ion movement decreases.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.360-363
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• 2005

Biomimetic actuators composed of cellophane with an electrically conducting polyaniline(PANI) film have been fabricated and tested in air ambience conditions doped with two different counter ions such as perchlorate (${ClO_4}^-$) and tetrafluoroborate (${BF_4}^-$). Fabrication of the trilayer CP//CELLOPHANE//CP substantially enhanced the tip displacement (13.2mm) compared to the small displacement (8.3mm) of the bilaye. CP//CELLOPHANE. The ion migration among layers is the main factor behind the expansion of cellophane, while the expansion/contraction of PANI are dependent on the redox reaction of the polymer. The displacement of the composite is dominated by the humidity content. This implies that the actuation principle is possibly due to the assistance of water existing.

• KSBB Journal
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• 제4권2호
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• pp.150-156
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• 1989

안정상태 일차원적 모델을 이용하여 막으로 덮힌 상업적인 산소 적극의 특성을 공기포화된 식염수에서 연구하였다. 전극은 세 개의 층으로 이루어져 있는데. 이는 외부 농도 경계층(용액), 반투성 막, 내부 전해질 용액 층으로 구분된다. 정체용액에서, 물은 외부 용액층으로부터 내부 전해질 용액쪽으로 열역학적 평형을 이룰 때까지 이동한다. 한편 유동 용액에서, 불은 수력학적 압력차 때문에 전해질 층의 두께가 막의 두께와 같아질 때까지 반대방향으로 이동한다.

• The Journal of Korean Physical Therapy
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• 제15권2호
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• pp.67-74
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• 2003

Nervous system is clinically important, and involved in most disorders directly or indirectly. It could be injury and be a source of symptoms. Injury of central or peripheral nervous system injury may affect that mechanism and interrupt normal function. An understanding of the concepts of axonal transport is important for physical therapist who treat injury of nerves. Three connective tissue layers are the endoneurium, perineurium, epineurium. Each has its own special structural characteristics and functional properties. The blood supply to the nervous system is well equipped in all dynamic and static postures with intrinsic and extrinsic vasculation. After nerve injury, alternations in the ionic compression or pressures within this environment may interfere with blood flow and, consequently conduction and the flow of axoplasm. The cytoskeleton are not static. On the contrary, elements of the cytoskeleton are dynamically regulated and are very likely in continual motion. It permits neural mobility. There are different axonal transport systems within a single axon, of which two main flows have been identified : First, anterograde transport system, Secondly, retrograde transport system. The nervous system adapts lengthening in two basic ways. The one is that the development of tension or increased pressure within the tissues, increased intradural pressure. The other is movements that are gross movement and movement occurring intraneurally between the connective tissues and the neural tissues. In this article, we emphasize the biologic aspects of nervous system that influenced by therapeutic approaches. Although identified scientific information in basic science is utilized at clinic, we would attain the more therapeutic effects and develop the physical therapy science.

• Journal of Electrochemical Science and Technology
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• 제8권2호
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• pp.101-106
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• 2017

$Li_2SiO_3$ was used as a coating material to improve the electrochemical performance of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$. $Li_2SiO_3$ is not only a stable oxide but also an ionic conductor and can, therefore, facilitate the movement of lithium ions at the cathode/electrolyte interface. The surface of the $Li_2SiO_3$-coated $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ was covered with island-type $Li_2SiO_3$ particles, and the coating process did not affect the structural integrity of the $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ powder. The $Li_2SiO_3$ coating improved the discharge capacity and rate capability; moreover, the $Li_2SiO_3$-coated electrodes showed reduced impedance values. The surface of the lithium-ion battery cathode is typically attacked by the HF-containing electrolyte, which forms an undesired surface layer that hinders the movement of lithium ions and electrons. However, the $Li_2SiO_3$ coating layer can prevent the undesired side reactions between the cathode surface and the electrolyte, thus enhancing the rate capability and discharge capacity. The thermal stability of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ was also improved by the $Li_2SiO_3$ coating.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.330-333
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• 2003

Recently electrokinetic process is known to be a promising remediation technology for the contaminated soils with heavy metals, radionuclides, organic matters, and so on. The contaminants in electrokinetic technology are removed mainly by three mechanisms; electroosmosis, electromigration, and electrophoresis. When direct current is introduced between two electrodes planted in soil, a large amount of hydrogen ions is formed and moves from anode to cathode with the other cations contained in electrolyte. The water flow caused by tile movement of cations is called as electroosmosis. Especially for non-ionic pollutants, the electroosmotic flow(EOF) is the most important removal mechanism among them and transports contaminants from anode to cathode along the water flow. In this study, characteristics of electroosmotic flow was investigated according to the resistance state of soil. The decrease, maintenance, and increase of soil resistance could be obtained by controlling ions in soil. When the resistance of soil was decreasing or maintained, the EOF is proportional to electric current and voltage, respectively and when the resistance was increasing, the EOF is proportional to only electric current not voltage.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.186-190
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• 2004

The electrokinetic bioremediation employing electrolyte circulation method was carried out for the cleanup of phenanthrene-contaminated kaolinite, and microorganism used in the biodegradation of phenanthrene was Sphingomonas sp. 3Y. The electrolyte circulation method supplied ionic nutrientsand the microorganism into soil, and inhibited the significant pH change of soil by increasing the soil buffering capacity by providing phosphate buffer compounds. When the remediation process was conducted without surfactant, the removal efficiency of phenanthrene, at the initial concentration of 200 ppm, was 69% for only 7 days. Higher microbial population and lower phenanthrene concentration were observed in the anode and middle regions of soil specimen than in the cathode region. The higher density of microorganism was because the microbial movement was in the direction of the anode part due to the negative surface charge. When Triton X-100 and APG of 20 g/1 were used to improve the bioavailability of phenanthrene strongly adsorbed onto soil surface, about 90 and 39% of phenanthrene removal were obtained. Consequently, it was confirmed that the microorganism preferred APC to phenanthrene as carbon source and so the removal efficiency with APG decreased less than that without APG.

• Smart Structures and Systems
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• 제24권2호
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• pp.223-231
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• 2019

The properties of Electroactive Polymer (EAP) materials are attracting the attention of engineers and scientists from many different disciplines. From the point-of-view of robotics, Ionic Polymer Metal Composites (IPMC) belong to the most developed group of the EAP class. To allow effective design of IPMC-actuated mechanisms with large induced strains, it is necessary to have adequate analytical tools for predicting the behavior of IPMC actuators as well as simulating their response as part of prototyping methodologies. This paper presents a novel IPMC motor construction. To simulate the bending behavior that is the dominant phenomenon of motor movement process, a nonlinear model is used. To accomplish the motor design, the IPMC model was identified via a series of experiments. In the proposed model, the curvature output and current transient fields accurately track the measured responses, which is verified by measurements. In this research, a three-dimensional Finite Element Method (FEM) model of the IPMC motor, composed of IPMC actuators, simultaneously determines the mechanical and electrical characteristics of the device and achieves reliable analysis results. The principle of the proposed drive and the output signals are illustrated in this paper. The proposed modelling approach can be used to design a variety of controllers and motors for effective micro-robotic applications, where soft and complex motion are required.

• 한국물환경학회지
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• 제27권1호
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• pp.115-119
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• 2011

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capillary itself is 0.012, 0.016, 0.024, 0.027 cm, and experiments were performed at $22^{\circ}C$. As a result, the height of the capillaries decreased with increasing capillary diameter, and the solution temperature but increased with increasing concentration. Changes in the height of the capillaries are interpreted to related with surface tension by the Young-Laplace equation. Also on the mobility of groundwater, the increase of water and soil temperatures can be significant factors caused by ion strength and global warming as well as pores in the soil particles. The results of this study is considered to provide the basic data on the behavior of groundwater in the soil environment.