Title :
Fabrication and characterization of an integrated thermal microsystem
Author :
Lee, Man ; Cheung, Luthur Siu Lun ; Lee, Yi-Kuen ; Wong, Man ; Zohar, Yitshak
Author_Institution :
Dept. of Mech. Eng., Hong Kong Univ. of Sci. & Technol., China
fDate :
30 Jan.-3 Feb. 2005
Abstract :
A thermal microsystem, integrated with pressure and temperature microsensors, is fabricated to study convective boiling under uniform heat flux boundary condition. Utilizing a wafer bond and etch back technology, the heat source, temperature and pressure sensors are separated from the fluid flow by a membrane only 1.5μm in thickness; thus, allowing experimentally good control of the thermal boundary conditions. Temperature distributions for various input power levels have been measured to obtain the boiling curves. The conditions corresponding to the onset of two phase flow, with boiling plateau, and the critical heat flux (CHF) are clearly distinguishable. Simultaneously, time-dependent pressure signals have also been recorded. In single liquid phase flow, the pressure is constant with time. However, in two phase flow, strong pressure fluctuations occur with certain frequencies. The qualitative visualizations of the evolving flow patterns have been correlated with the quantitative temperature and pressure measurements.
Keywords :
etching; microsensors; pressure sensors; temperature distribution; temperature sensors; wafer bonding; boiling curves; boiling plateau; convective boiling; critical heat flux; etch back technology; fluid flow; heat source; integrated thermal microsystem; pressure measurements; pressure microsensors; pressure sensors; single liquid phase flow; temperature distributions; temperature measurements; temperature microsensors; temperature sensors; thermal boundary conditions; time-dependent pressure signals; two phase flow; uniform heat flux boundary condition; wafer bond technology; Biomembranes; Boundary conditions; Etching; Fabrication; Fluid flow; Microsensors; Sensor phenomena and characterization; Temperature sensors; Thermal sensors; Wafer bonding;
Conference_Titel :
Micro Electro Mechanical Systems, 2005. MEMS 2005. 18th IEEE International Conference on
Print_ISBN :
0-7803-8732-5
DOI :
10.1109/MEMSYS.2005.1454003