• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.425-428
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• 2006

Recently, Direct Methanol Fuel Cell (DMFC) for portable devices has been received much attention because DMFC has a possibility of higher energy density than electrical batteries and smaller size than other fuel cells. This paper presents the fabrication and test of a thermopneumatic microactuator with a phase change for DMFC. A microactuator consists of an inlet an outlet a chamber, a heater and a sensor of resistance temperature detector(RTD). The micoractuator is fabricated by the spin-coating process, the lithograph process, the deep RIE process and so on. The total size of microactuator is $20{\times}20{\times}0.53mm^3$. When the current is applied, the heater heats liquid in chamber. As a result the liquid vaporizes. The response of temperature in the chamber was measured using thermocouple The changed temperature is $3^{\circ}C$ for 5 sec at 0.032W.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.175-176
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• 2006

Electrowetting is prevailing for its various applicability on lap-on-a-chip, and MEMS devices, such as a pump, lens, micro-actuator in the micro-TAS technology. In the usual electrowetting, an AC power is preferred to DC practically. The AC electric field delays the contact angle-saturation, decreases the hysterisis, and is more stable in the view point of dielectric strength. But researches for AC electric field on electrowetting have not been reported very much yet. The different effect of AC on the electrowetting system, especially the effect of a frequency needs to be understood more concretely. In this work, the usual system for electrowetting, water droplet on the dielectric coated electrode (EWOD) is analyzed. Experimental study on the response of contact angles on input frequencies is performed. The simple circuit-model for EWOD system is considered to explain the experimental results. For more concrete understanding, the system is analyzed numerically, where simple AC-conduction model is used. Wetting tensions are analyzed under various input frequency to excavate the experimental results for the responses of the system on input frequencies.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.425-428
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• 2011

본 논문에서는 간단한 Maximum Power Point Tracking이 적용된 micro-scale의 빛에너지 하베스팅 회로를 제안한다. 에너지 변환기로는 온칩 PV cell 대신 이와 비슷한 출력을 하는 초소형 PV cell을 사용하였다. 적용된 MPPT는 PV cell의 개방전압($V_{OC}$)와 MPP전압($V_{MPP}$)과의 관계를 이용하였고 이는 pilot PV cell을 이용함으로써 가능하였다. 설계결과 MPPT control을 적용했을 때 부하가 큰 경우에도 대략 $V_{MPP}$ 전압을 부하에 공급함으로써 부하에 연결된 회로가 정상적으로 동작하는 것을 확인하였다. 제안된 회로는 TSMC 0.18um CMOS 공정으로 설계되었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.22-24
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• 1996

Small size DC motor control method for portable drug delivery system has been developed to be used for the actuator of insulins pump. The control method gives the controllabilities both in high speed(40-50 revolution per second(rps)) DC motor drive and also in low speed(0.5-1rps). In low speed mode DC motor is controlled to act like stepping motor and in high speed to optimize power consumption. To control both mode modified bang bang control is suggested. Using this method small size DC motor(spec.) speed is controlled from 0.2 rps to 50 rps. Experimental setup is developed using micro-processor(PIC16C73, Micro Chips co., USA), motor turns checking circuitry, small size DC motor for pager(SM1012, Samhong co., Korea) and gear box. Results from experiment meet need for vailable load condition which is require for portable drug delivery system.

• 한국의학물리학회지:의학물리
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• 제25권2호
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• pp.116-121
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• 2014

본 본문은 Bio-MEMS 공정으로 제작한 마이크로 세포 분석 바이오칩을 사용하여 적혈구의 광학적 특성을 전압으로 측정한 실험이다. Bio-MEMS 공정을 이용하여 세포의 원활한 이동과 측정 분석에 사용되는 글라스에 채널 패턴 에칭을 위하여 포토리소그래피(photolithography)와 산화완충식각(BOE: buffered oxide etchant) 공정 조건, 세포 분석과 정보 전달에 사용되는 광섬유의 에칭을 위하여 산화완충식각 공정 조건, 세포나 유체를 칩과 외부의 전달 등에 사용되는 글라스의 홀을 위하여 전기화학방전(ECD: electro chemical discharge) 공정 조건, 글라스 접합을 위한 자외선반응접합(UVSA: ultraviolet sensitive adhesives) 공정 조건을 정립하였다. 또한 유체나 세포의 흐름 제어를 위한 라미나 흐름 조건, 적혈구세포에 대한 산란빔 파형을 측정하였다. 적혈구 실험을 통하여 출력 광섬유의 각도에 따른 산란빔이 출력측의 광섬유각도가 $0^{\circ}$일 때 약 17 V, 각도가 $5^{\circ}$일 때 약 10 V, 각도가 $10^{\circ}$일 때 약 6 V, 각도가 $15^{\circ}$일 때 약 4 V의 전압(Vpp)으로 측정되었다. 따라서 마이크로 세포 분석 바이오칩 제작의 소형화, 단순화, 공정신간 단축, 정량화하였고 적혈구의 광학적 특성을 측정을 측정함으로써 의공학(biomedical), 바이오칩공학(biochip), 반도체공학(semiconductor), 생물정보학(bioinformatics) 등의 응용과학 분야 발전에 기여할 것으로 기대한다.

• 융합정보논문지
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• 제9권5호
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• pp.158-164
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• 2019

최근에는 환자의 귀에 거슬리는 소음을 발생시키는 치과 용 핸드 피스의 소음을 줄이기 위한 많은 연구가 주목 받고 있습니다. 일반적으로 배기 밸브, 기계 또는 자동차의 공기 펌프 내부에 흡음재를 추가하는 방법이 기계적 소음을 줄이는 최적의 방법으로 널리 보고됩니다. 본 논문에서는 EPP 기판의 미세 다공성 구조를 이용한 새로운 UV 레이저 가공 및 흡음 효율 향상을 위한 치과 용 핸드 피스의 제조 방법을 연구 하였다. 슬라이스 된 EPP 기판의 표면에 UV 레이저 가공으로 다수의 미세 크기 기공이 만들어졌다. 본 실험에서 다양한 휴대용 기계에 적용할 수 있는 우수한 잠재력을 가진 마이크로 다공성 EPP 기판은 치과 용 핸드 피스 내부의 마이크로 머플러의 흡음 구조에 적용되었고 핸드피스의 소음을 측정한 결과 적용전의 핸드피스에 비해 약 4dB의 흡음효과를 나타내었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.635-638
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• 2001

Photovoltaic (PV) pumping systems with maximum power point tracking (MPPT) technique aims at obtaining the highest possible power to the pump under various insolation and temperature, thus overcomes the mismatch between the photovoltaic panel and the pumping load. A simple method of tracking the maximum power points and forcing the system to operate close to these points is presented in this paper. The MC68HC908GP32 micro control unit (MCU) is employed to implement the proposed MPPT controller. Experimental results will also show the performances of the photovoltaic pumping system with the MPPT technique.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.288-290
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• 2006

This paper presents the real-time water tank wireless control in a ship using duplex RF modules and PLC(Programmable logic Controller). The purpose of this paper is developing HMI(Human Machine Interface) for automation equipments. The system can low a cost because long wires are no more used. Analog signals of the water gauge and flow meter are changed to discrete signals by the micro-processor. The PLC checks the volume of water and runs On or Off of the valve and pump. Duplex RF modules send and receive data between the water tank and control room. Everywhere the Internet is used, operators are able to check the status of the system by the web-server.

• Journal of Mechanical Science and Technology
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• 제19권2호
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• pp.649-654
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• 2005

This paper presents fabrication and drive test of a peristaltic PDMS micropump actuated by the thermopneumatic force. The micropump consists of the three peristaltic-type actuator chambers with microheaters on the glass substrate and a microchannel connecting the chambers and the inlet/outlet port. The micropump is fabricated by the spin-coating process, the two-step curing process, the JSR (negative PR) molding process, and etc. The diameter and the thickness of the actuator diaphragm are 2.5 mm and $30{\mu}m$, respectively. The meniscus motion in the capillary tube is observed with a video camera and the flow rate of the micro pump is calculated through the frame analysis of the recorded video data. The maximum flow rate of the micropump is about $0.36\;{\mu}L/sec$ at 2 Hz for the zero hydraulic pressure difference when the 3-phase input voltage is 20 V.

• Biomolecules & Therapeutics
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• 제14권1호
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• pp.45-49
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• 2006

The purpose of this study was to clarify the efflux transport system of choline from brain to blood across the blood-brain barrier (BBB) in rats using the brain efflux index (BEI) method. $[^3H]$Choline was micro-injected into parietal cortex area 2 (Par2) of the rat brain, and was eliminated from the brain with elimination halflife of 45 min. The BBB efflux clearance of $[^3H]$choline was about 124 mL/min/g brain, which was determined from combination of an elimination rate constant $(1.54X10^{-2}min^{-1})$ and the distribution volume in the brain (8.05 mL/g brain). The efflux of $[^3H]$choline was inhibited by unlabeled choline in a dose-dependent manner and was significantly inhibited by cationic substrates, such as hemicholinium-3 and tetraethylammonium (TEA). These results suggest that the BBB may act as an efflux pump for choline to reduce the excessive choline concentration in the brain interstitial fluid.