• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.453-456
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• 2005

Significance verification of electric fabric compared with existing electrode is very useful for the wearable and ubiquitous healthcare. In this paper, we verified the significance between Ag/AgCl electrode and electric fabric in dry-normal condition through heart rate variability analysis. We can find 98 % or more similarity about low frequency and high frequency which is important parameter for the heart rate variability analysis between two different electrodes in experiment. From this result, we confirmed that the power spectral density of low frequency, high frequency component from the electric fabric has high similarity compared with the result of heart rate variability from Ag/AgCl electrode in dry-normal condition.

• Smart Structures and Systems
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• 제29권5호
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• pp.705-714
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• 2022

In this paper, the effect of magnetic field on the vibration behavior of a Magnetorheological elastomer (MRE) sandwich MEMS actuated by electrostatic actuation with conductive skins are examined within the multiple scales (MMS) perturbation method. Magnetorheological smart materials have been widely used in vibration control of various systems due to their mechanical properties change under the influence of different magnetic fields. To investigate the vibrational behavior of the movable electrode, the Euler-Bernoulli beam theory, as well as Hamilton's principle is used to derive the equations and the related boundary conditions governing the dynamic behavior of the system are applied. The results of this study show that by placing the Magnetorheological elastomer core in the movable electrode and applying different magnetic fields on it, its natural vibrational frequency can be affected so that by increasing the applied magnetic field, the system's natural frequency increases. Also, the effect of various factors such as the electric potential difference between two electrodes, changes in the thickness of the core and the skins, electrode length, the distance between two electrodes and also change in vibration modes of the system on natural frequencies have been investigated.

• 전기전자학회논문지
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• 제25권3호
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• pp.445-450
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• 2021

생체임피던스 측정법은 편리성, 저비용 및 저가의 장치를 이용하여 생체정보 획득 및 피부 병 진단 등에 사용 가능한 장치이다. 본 연구에서는 생체 삽입형으로 생체 정보를 획득하기 위해서 동물 생체 모델링을 통한 시뮬레이션 연구와 직접 제작한 건식용 금 전극을 이용하여 생체임피던스를 측정하였다. 동물 조직의 피하부위에 전극을 삽입하여 2 전극법으로 100 uA, 1-100 kHz 주파수를 인가하여 임피던스를 측정하였다. 측정결과 전극의 사이즈를 5 mm전극기준으로 7.5 mm, 10 mm전극과 비교하여 저항을 측정한 결과 5 mm 전극에서 높게 측정됨을 확인할 수 있다. 5 mm전극을 기준으로 7.5 mm 전극은 전체 주파수 범위에서 평균 1.49 %차이를 발견하였고, 10 mm 전극은 2.624 %로 임피던스가 차이남을 확인하였다. 향후, 연구결과는 생체 삽입형 심전도 센서 전극 설계 및 제작 등에 활용가치가 있을 것으로 사료된다.

• 한국정밀공학회지
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• 제22권2호
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• pp.180-187
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• 2005

This paper is focused on the development of the flexible electrode for disc-type polymer actuators using Segmented Polyurethane(SPU). This paper consists of two parts. The one is about the mechanical property such as elastic modulus. these parameters mainly affect behaviors of polymer actuators and the other is about the electro-chemical property such as the surface resistance of the composite electrode affects the strength of electrostatic force, results in the deformation of polymer actuators. The Young's modulus was measured by UTM. As result, by increasing the modulus of a body of polymer actuators, the maximum displacement of polymer actuators are decreased. The surface resistance of the electrode was measured by 4 point probe system. Compared with the conductive silver grease, the displacement of polymer actuators using carbon black(CB) composite electrodes is comparably small but CB composite electrode should be the practical approach for the improvement of the performance of all-solid actuators, compared with another types of electrode materials.

• 대한화학회지
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• 제20권2호
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• pp.129-135
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• 1976

4-전극 측정 용기와 정전위 전자회로를 써서 직독식 전기전도도 측정장치를 고안하여 KCl, HCl등 전해질 용액의 전기전도도를 측정하였다. 이 장치는 상용되고 있는 브릿지회로와 2-전극 용기를 쓰는 방법에서 당면하는 어려운 문제들, 특히 전극에서의 전기 이중층의 존재와 파라디임피던스 등으로 나타나는 전기화학적으로 복잡한 성질들로 인한 문제들을 피하여 정밀하고 간편한 측정에 쓰이도록 만들었다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1996년도 추계학술발표회논문집
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• pp.125-129
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• 1996

This study describes that electrical breakdown of liquid nitrogen which is influenced with bubble has been investigated as liquid nitrogen is used coolant of high temperature(T/sub c/) superconductivity. In order to investigate breakdown of liquid nitrogen, we formed electrode system of parallel and vertical configuration toward gravitutional direction. In case of changing with electrode configuration of equal electrode and gap spacing in uniform and nonuniform electric field bubble behavior is changed. In result of that, breakdown voltage is changed. Therefore, this study proved that electrode configuration must be formed the smallest existing probability of bubble between two electrodes in order to increase breakdown strength of liquid nitrogen at atmosphere pressure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.598-600
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• 2002

To improve the luminance and efficiency of AC PDP, the effects of a square pulse applied to the address electrode during a sustain-period is investigated. Through this experiment, we confirmed the improvement of luminance and efficiency. We performed the temporal behavior measurement for the light emitted from AC PDP at floating state of the address electrode and at various auxiliary voltages (including ground state) applied to the address electrode using the scanned point detecting system. In the case of using an auxiliary voltage pulse, emission starts at the inner edges of the anode and cathode simultaneously. Also, we obtained the larger two discharge volumes compared with the normal sustain discharge where address electrode is floated.

• 소음진동
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• 제8권4호
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• pp.632-642
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• 1998

A method based on finite element discretization is developed for optimizing the polarization profile of PVDF film to create the modal transducer for specific modes. Using this concept, one can design the modal transducer in two-dimensional structure having arbitrary geometry and boundary conditions. As a practical means for implementing this polarization profile without repoling the PVDF film the polarization profile is approximated by optimizing electrode patterns, lamination angles, and poling directions of the multi-layered PVDF transducer. This corresponds to the approximation of a continuous function using discrete values. The electrode pattern of each PVDF layer is optimized by deciding the electrode of each finite element to be used or not. Genetic algorithm, suitable for discrete problems, is used as an optimization scheme. For the optimization of each layers lamination angle, the continuous lamination angle is encoded into discrete value using binary 5 bit string. For the experimental demonstration, a modal sensor for first and second modes of cantilevered composite plate is designed using two layers of PVDF films. The actuator is designed based on the criterion of minimizing the system energy in the control modes under a given initial condition. Experimental results show that the signals from residual modes are successfully reduced using the optimized multi-layered PVDF sensor. Using discrete LQG control law, the modal peaks of first and second modes are reduced in the amount of 12 dB and 4 dB, resepctively.

• 한국소음진동공학회논문집
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• 제26권5호
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• pp.511-517
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• 2016

This paper presents dynamic characteristics of a new actuator using magneto-rheological(MR) fluid between two electrode type coils. The concept of the actuator is to strengthen the force due to the magnetic field produced by the electrode-coil for MR fluid. The amount and direction of current input to the electrode-coils decide the characteristics of contraction-mode and extension-mode. For achieving the required actuating displacement and actuating force, the yield stress of the MR fluid between two electrode-coils is precisely changed by the input current. In this work, the MR fluid is operated in squeeze mode. The experimental results shown in this paper depict that it can be applied in the micro-level displacement and vibration control system.

• 대한기계학회논문집B
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• 제38권4호
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• pp.357-363
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• 2014

리튬이온전지의 다공성 전극내에서 전해액 주입 후 발생하는 함침현상에 관하여 격자 볼츠만법을 이용하여 수치해석적으로 연구하였다. 다공성 전극은 전극 제조 중 압연공정을 거치므로 압축된 전극의 공극률과 두께변화가 발생하여 전해액 함침성에 영향을 미치게 된다. 본 연구에서는 2 차원 격자 볼츠만법을 통하여 압축률에 따른 전해액 분포와 포화도 변화를 제시하였다. 압축된 전극에서의 전해액 침투경로의 변화는 기공의 두께방향 크기 감소에 기인하며, 따라서 전극의 함침성이 크게 감소하였음을 확인하였다.