Heat Convection in Microchannels: single phase and two-phase flows
The study of heat convection in microchannels initiated from the micro cooling devices for microelectronics made in Stanford University in 1980s. Although there were research results all over the world to characterize the heat transfer performance under different boundary conditions, these results were often contradictory because it was difficult to control all the experimental parameters including the fluid properties, the fluid and thermal conditions at the inlet, outlet and the microchannel walls. Recently, we are able to integrate micro heaters, temperature sensors, piezoresistive pressure sensors with microchannels for two-phase flow study.
Fabricated Device
Experimental Result: Active/Non-active Nucleation Sites
BOUNDARY CONDITIONS
Two-Phase Flow: Flow Patterns Visualization
Experimental Result:
Two Phase Flow Pattern-Intermittent Flow
Device Packaging
Reference:
M. Lee, L.S.L. Cheung, Y.-K. Lee, M. Wong, Y. Zohar, "Height Effect on Nucleation-Site Activity in Microchannel Convective Boiling," IEEE MEMS 2004, Maastricht, Netherlands, Jan 25-29, pp.300-303, 2004.
L.S.L. Cheung, Y.-K. Lee, M. Wong and Y. Zohar,"Size-dependent Bubble Dynamics in a Microchannel Heat Sink," IEEE MEM 2005, Miami, USA, pp.670-673, 2005.
M. Lee, Y.-K. Lee, M. Wong and Y. Zohar, "Fabrication and Characterization of an Integrated Thermal Microsystem," IEEE MEMS 2005, Miami, USA, pp.610-613, 2005.
M. Lee, LS.L. Cheung, Y.-K. Lee and Y. Zohar, "Height Effect on Nucleation-Site Activity and Size-Dependent Bubble Dynamics in Microchannel Convective Boiling," Journal of Micromechanics and Microengineering, Vol. 15, pp.1-9, 2005.
Applications:
Single phase flow: thermal micro accelerometers, microchannel-based PCR for DNA amplification.
Two-phase flow: Cooling of Microelectronic chips and laptop computers: micro heat pipe and micro heat sink
Thermal lysing of biological cells.
Previous works by Prof Yitshak Zohar and his co-workers at HKUST
Book:
Heat Convection in Micro Ducts, Yitshak Zohar, Kluwer Academic Publishers, 2002.
Research Papers:
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L.Jiang, M. Wong and Y. Zohar, Phase change in micro-channel heat sinks with integrated temperature sensors. J. Microelectromech. Syst., Vol. 8, No.4, pp.358-365, 1999.
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L. Jiang, Y. Wang, M. Wong and Y. Zohar, Fabrication and characterization of a microsystem for microscale heat transfer study. J. Micromech. Microeng., Vol. 9, No. 4 pp.422-428, 1999.
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L. Jiang, M. Wong and Y. Zohar, Transient temperature performance of an integrated thermal microsystem. J. Micromech. Microeng., Vol. 10, No. 3, pp.466-476, 2000.
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L.Jiang, M. Wong and Y. Zohar, Forced convection boiling in a microchannel heat sink. J. Microelectromech. Syst., Vol. 10, No. 1, pp.80-87, 2001.
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M. Lee, Y. Y. Wong, M. Wong and Y. Zohar Two-phase flow boiling in a microchannel heat sink. ASME International Mechanical Engineering Congress and Exposition. 2001, pp.567-73. New York, NY, 2001.
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M. Lee, M. Wong and Y. Zohar, Integrated micro-heat-pipe fabrication technology. J. Microelectromech. Sys., Vol.12, No.2, pp.138-46, 2003.
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M. Lee, Y. Y. Wong, M. Wong and Y. Zohar Size and shape effects on two-phase flow patterns in microchannel forced convection boiling, J. Micromech. & Microeng., Vol.13, No.1, pp.155-64, 2003.
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M. Lee, M. Wong and Y. Zohar, Characterization of an integrated micro heat pipe. J. Micromech. & Microeng., Vol.13, No.1, pp.58-64, 2003.
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M. Lee, M. Wong, Y. Zohar, Design, fabrication and characterization of an integrated micro heat pipe. IEEE MEMS '02, pp.85-88, Las Vegas, NV, USA, 2002.
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M. Lee, Y.Y. Wong, M. Wong and Y. Zohar, Size and shape effects on two-phase flow instabilities in microchannels, IEEE MEMS '02, pp.28-31, Las Vegas, NV, USA, 2002.
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L. Jiang, M. Wong and Y. Zohar, Unsteady characteristics of a thermal microsystem, Sensors & Actuators A, Vol.A82, No.1-3, pp.108-113, 2000.
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L. Jiang, M. Wong and Y. Zohar, A micro-channel heat sink with integrated temperature sensors for phase transition study, IEEE MEMS '99, pp.159-164, 1999.