Journal of Applied Science and Engineering

Published by Tamkang University Press


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Horng-Jou Wang1, Hsin-Chang Tsai1, Hwang-Kuen Chen1 and Tai-Kang Shing This email address is being protected from spambots. You need JavaScript enabled to view it.1

1MEMS R&D Department, Research Center, Delta Electronics, Inc. Taoyuan, Taiwan 333, R.O.C.


Received: March 4, 2005
Accepted: June 2, 2005
Publication Date: September 1, 2005

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The capillarity of micro grooves with rectangular cross-section is studied theoretically and experimentally in this paper. The Helmholtz free energy method is used to predict the capillarity as the groove is placed vertically and inserted the bottom end into the liquid. In the experiment, micro grooves are first constructed by the thick photoresist patterned by photolithography method and then a thin copper layer is deposited on their surface to improve the hydrophilic property of liquid-solid interface. It is shown that the theoretical and experimental results are in good agreement. Furthermore, the capillary limits of micro grooved heat pipes are investigated. The effects of groove’s width and number on the capillary limit contributed from the maximum capillary pumping pressure and the pressure drops due to the friction and gravitational force are calculated. A workable geometry range of micro grooves for a heat pipe designed to transport a specific heat rate can be determined by these developed tools.

Keywords: Capillarity, Micro Grooves, Heat Pipes, Capillary Limit


  1. [1] Ziaie, B., Baldi, A., Lei, M., Gu, Y. and Siegel, R. A., “Hard and Soft Micro-machining for BioMEMS: Review of Techniques and Examples of Applications in Microfluidics and Drug Delivery,” Advanced Drug Delivery Reviews, Vol. 56, pp. 145172 (2004).
  2. [2] Chi, S. W., Heat Pipe Theory and Practice: A Sourcebook, Hemisphere, Washington (1976).
  3. [3] Faghri, A., Heat Pipe Science and Technology, Taylor & Francis, Washington (1995).
  4. [4] Peterson, G. P., An Introduction to Heat Pipes-Modelling, Testing and Applications, John Wiley and Sons, NY, U.S.A. (1994).
  5. [5] Garner, S. D., “Heat Pipes for Electronics Cooling Applications,” Electronics Cooling, Vol. 2, pp. 1823 (1996).
  6. [6] Zaghdoudi, M. C., Tantolin, C. and Godet, C., “Use of Heat Pipe Cooling Systems in the Electronics Industry,” Electronics Cooling, Vol. 10, pp. 18 (2004).
  7. [7] Khrustalev, D. and Faghri, A., “Thermal Characteristics of Conventional and Flat Miniature AxiallyGrooved Heat Pipes,” ASME, Journal of Heat Transfer, Vol. 119, pp. 10481054 (1995).
  8. [8] Hopkins, R., Faghri, A. and Khrustalev, D., “Flat Miniature Heat Pipes with Micro Capillary Grooves,” ASME, Journal of Heat Transfer, Vol. 121, pp. 102 109 (1999).
  9. [9] Suh, J. S. and Park, Y. S., “Analysis of Thermal Performance in a Micro Flat Heat Pipe with Axially Trapezoidal Groove,” Tamkang Journal of Science and Engineering, Vol. 6, pp. 201206 (2003).
  10. [10] Ma, H. B. and Peterson, G. P., “Experimental Investigation of the Maximum Heat Transport in Triangular Grooves,” ASME, Journal of Heat Transfer, Vol. 118, pp.740746 (1996).
  11. [11] Carey, V. P., Liquid-Vapor Phase-Change Phenomena, Hemisphere, Washington (1992).
  12. [12] Yang, L. J., Yao, T. J. and Tai, Y. C., “The Marching Velocity of the Capillary Meniscus in a Microchannel,” Journal of Micromechanics and Microengineering, Vol. 14, pp. 220225 (2004).
  13. [13] Tseng, F. G. and Yu, C. S., “High Aspect Ratio Ultrathick Micro-stencil by JSR THB-430N Negative UV Photoresist,” Sensors and Actuators A, Vols. 9798, pp. 764 770 (2002).
  14. [14] Incropera, F. P. and DeWitt, D. P., Fundamentals of Heat and Mass Transfer, John Wiley & Sons, NY, U.S.A. (1996).