• 제목/요약/키워드: Micro Heater

검색결과 159건 처리시간 0.025초

마이크로채널 기판에서 비정상 복합 열전달의 수치적 연구 (NUMERICAL STUDY OF TRANSIENT CONJUGATE HEAT TRANSFER IN A MICRO-CHANNEL SUBSTRATE)

  • 이희준
    • 한국전산유체공학회지
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    • 제17권4호
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    • pp.87-92
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    • 2012
  • A numerical study of transient conjugate heat transfer on micro heater in a micro-channel substrate under pulsed heating was conducted. It was found that the time constant is not affected by the pulse heating magnitude at same operating condition. Furthermore, the time constant increases with low substrate thermal diffusivity, low Reynolds number, and large channel diameter. Since the time constant is a dominant parameter to characterize transient heat transfer, it should be considered for transient convective heat transfer coefficient.

상 변화방식 마이크로 액츄에이터의 제조 및 성능에 관한 연구 (The fabrication and characterization of a phase change type micro actuator)

  • 박승인;황준영;이상호;강경태;강희석;강신일
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1433-1438
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    • 2007
  • Characteristics of a phase change type micro actuator have been studied. The micro actuator has been designed for a micro-pump in an active direct methanol fuel cell(DMFC), consisting of an actuating chamber, a membrane, an electric heater, and a sensor of resistance temperature detector (RTD). In the present study, researches have been focused on the response of the actuator to control algorithm of the heater. The experiments demonstrated that the displacement of the membrane increase with temperature variation which is a function of applied voltage, duty ratio, and operating frequency of heating. The results also showed that operation of the actuator with high voltage at small duty of heating is more efficient than the same power consumption of heating with low voltage at large duty.

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수소가스 감지용 가연성 가스센서 제작을 위한 요소기술 개발 (Development of Core Technologies for Integrating Combustible Hydrogen Gas Sensor)

  • 윤의중;박형식;이석태;박노경
    • 한국전기전자재료학회논문지
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    • 제20권3호
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    • pp.228-233
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    • 2007
  • Core technologies for integrating hydrogen gas sensor were investigated. In this study, the thermally isolated micro-hot-plate with areas of $100{\times}100-260{\times}260{\mu}m^2$ was fabricated by utilizing surface micromachining technique that provides better manufacturing yield than bulk micromachining counterpart. The optimum design of the sensor was peformed by analyzing the thermal profile of the structure obtained from a ANSYS simulator. The 400-nm-thick polysilicon films doped with phosphorus, the 300-nm-thick aluminum films, and the 200-nm-thick $SnO_2$(or ZnO)films were used as the micro-heater material, the temperature sensor material, and the gas sensitive material, respectively. The experimental results show that the developed gas sensors can detect $H_2$ concentration as low as 1 ppm.

SOI 멤브레인과 트랜치 구조상에 제작된 발열저항체형 마이크로 유량세선의 특성 (Characteristics of Hot-Film Type Micro-Flowsensors Fabricated on SOI Membrane and Trench Structures)

  • 정귀상;김미목;남태철
    • 한국전기전자재료학회논문지
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    • 제14권8호
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    • pp.658-662
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    • 2001
  • This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD(resistance thermometer device) and micro-heater on the SOI(Si-on-insulator) membrane and trench structures, in which MGO thin-film was used as medium layer in order to improve adhesion of Pt thin-film to SiO$_2$ layer. Output voltages increased due to increase of heat-loss from sensor to external. The output voltage was 250 nV at N$_2$ flow rate of 2000 sccm/min, heating power of 0.3 W. The response time($\tau$:63%) was about 42 msec when input flow was step-input. The results indicated that micro-flowsensors with the SOI membrane and trench structures have properties of a high-resolution and ow consume power.

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MEMS Application of Quenching Effect to a Novel Micro Solid Rocket

  • Ebisuzaki, Hideyo;Nagayama, Kunihito;Ikuta, Tatsuya;Takahashi, Koji
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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    • pp.601-604
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    • 2004
  • Precise position and attitude control of pico-satellite requires huge number of impulses of the order of 10$^{-6}$ Ns. MEMS solid rocket array is a promising propulsion system but the higher degree of miniaturization causes unreliable operation mainly due to quenching. In order to breakthrough this situation, a novel design of solid micro-rocket is proposed, which generates tiny impulses repetitively from a single rocket not from array. This unique micro-rocket is based on the utilization of quenching, which causes propellant reaction to sustain only in a small area. A test chip of a micro solid propellant tank and micro heater array is fabricated and ignition test is conducted. Obtained results show the feasibility of this concept and future direction of this quenching-based propulsion is discussed.

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Fabrication of low power micro-heater for micro-gas sensor II. Characteristics of micro-gas sensor

  • 정완영;이상문;강봉휘;장동근;이덕동;노보루 야마조애
    • 센서학회지
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    • 제6권3호
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    • pp.237-244
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    • 1997
  • A new planar-type microsensor, which had a platinum heater and a sensing layer on the same plane was fabricated on silicon substrate with stress-relieved PSG(phosphosilicate glass)/$Si_{3}N_{4}$(800nm/150nm) diaphragm. The proposed planar-type microsensor could be fabricated by simple silicon process using only 3 masks for photolithography process compared with 5 or 6 masks of the typical micro-gas sensor. The thermal properties of the microsensor from thermal simulation were compared with those of the fabricated microheater. Although there are some discrepancy between the simulation result and the result from the fabricated microheater, the thermal simulation by FEM was proved to be an useful method to evaluate the thermal properties of microheater. The sensing characteristics of the fabricated microsensor with the planar-type heater were investigated also.

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NiCr 박막의 발열 특성 개선을 위한 순차적 이중 열처리 방법 연구 (Gradational Double Annealing Process for Improvement of Thermal Characteristics of NiCr Thin Films)

  • 권용;노효섭;김남훈;최동유;박진성
    • 한국전기전자재료학회논문지
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    • 제18권8호
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    • pp.714-719
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    • 2005
  • NiCr thin film was deposited by DC magnetron sputtering on $A;_2O_3$/Si substrate with NiCr (80:20) alloy target. NiCr thin films were annealed at $300^{\circ}C,\;400^{\circ}C,\;500^{\circ}C,\;600^{\circ}C,\;and\;700^{\circ}C$ for 6 hr in $H_2$ after annealing at $500^{\circ}C$ for 6hr in air atmosphere, respectively. To analyze NiCr thin film properties, the changes of its micro structure were Investigated through field emission scanning electron microscope (FESEM). X-ray photoelectron spectroscopy (XPS) was used to analyze a surface of NiCr thin film. Resistance of NiCr thin film was measured by 4-point probe technique. The generated heats were measured by infrared thermometer through the application of DC voltage (5 V/l2 V). NiCr thin film treated by gradational double annealing process had uniform and small grains. Maximum temperature generated heat by NiCr micro heater was $173^{\circ}C$. We expect that our results will be a useful reference in the realization of NiCr micro heater.

나노 결정 SnO2와 백금 박막히터를 이용한 접촉연소식 마이크로 가스센서의 감응특성 연구 (Catalytic combustion type hydrogen micro gas sensor using thin film heater and nano crystalline SnO2)

  • 한상도;홍대웅;한치환;전일수
    • 센서학회지
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    • 제17권3호
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    • pp.178-182
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    • 2008
  • Planar type micro catalytic combustible gas sensor was developed by using nano crystalline $SnO_2$ Pt thin film as micro heater was deposited by thermal evaporation method on the alumina substrate. The thickness of the Pt heater was around 160 nm. The sensor showed high reliability with prominent selectivity against various gases(Co, $C_3H_8,\;CH_4$) at low operating temperature($156^{\circ}C$). The sensor with nano crystalline $SnO_2$ showed higher sensitivity than that without nano crystalline $SnO_2$. This can be explained by more active adsorption and oxidation of hydrogen by nano crystalline $SnO_2$ particles. The present planar-type catalytic combustible hydrogen sensor with nano crystalline $SnO_2$ is a good candidate for detection of hydrogen leaks.

마이크로 가스터빈 열병합장치 성능특성 연구 (Study on the Performance Characteristics of Micro Gas Turbine (MGT) Co-generation System)

  • 허광범;김재훈
    • 한국소음진동공학회논문집
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    • 제16권9호
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    • pp.964-970
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    • 2006
  • Micro gas turbine(MGT) has received attention recently as small-scale distributed power sources. With characteristics such as their small size, lightweight, low maintenance cost and minimal vibrations during operation, they are expected to become widespread in a wide range of ' applications, including residential and small-scale industrial use. It is very easier to start-up and stop the MGT system which is the friendly environmental power system has just below the 9ppm NOx emmission and good quality of noise level. The exhaust heat emitted by the MGT is in the form of about $300^{\circ}C$ clean exhaust gas. The exhaust gas is suitable for absorption chiller/heater system. 1 has researched performance characteristics of the 60 kW class MGT-absorption chiller-heater system in the local condition. Variations of heat recovery from exhaust gas has measured according to micro gas turbine output of 15, 30, 45, 60kW. From those results, the performance of the MGT-absorption chiller/heater system has been evaluated.