Evaporative heat transfer from ten-micron square open-top micro-channels is investigated experimentally. The channels are fabricated by spinning ten microns of SU-8 on a two micron thick silicon membrane and using a photolithography process to create micro channels in radial and annular patterns. The working fluid, FC77, is pumped by capillary forces into the channels from a reservoir at the edge of the silicon membrane. Electrical power is dissipated in a thin-film heater in the center of the membrane. The liquid front of working fluid in the channels is visualized with a long-distance microscope and CCD camera. Sensible heat conducted radially out of the membrane is measured with two concentric annular PRT’s. The mass of working fluid evaporated from the micro-channels is determined gravimetrically. A global energy balance including latent and sensible heat transfer out of the system is then tabulated. The study shows that only five to ten percent of the power going into the membrane is carried away by evaporation while the remaining ninety to ninety-five percent of the power is conducted out along the membrane.

1.
Chen
HR
;
Gau
C
;
Dai
BT
;
Tsai
MS
.
A monolithic fabrication process for a micro-flow heat transfer channel suspended over an air layer with arrays of micro-sensors and heaters
.
Sensors and Actuators A
,
108
(
2003
)
81
85
.
2.
Chen
ZQ
;
Cheng
P.
.; and
Zhao
TS.
An experimental analysis of two-phase flow and boiling heat transfer in bi-dispersed porous channels
.
Int. Commun. Heat Mass Transfer
,
27
(
3
) (
2000
)
293
302
.
3.
Chuang
YJ
;
Tseng
FG
;
Cheng
JH
;
Lin
WK
,
2003
A novel Fabrication method of embedded micro-channels using SU8 thick-film photoresists
.
Sensors and Actuators
,
103
,
64
69
.
4.
Ichikawa
N
;
Hosokawa
K
;
Maeda
R
,
2004
.
Interface motion of capillary-driven flow in rectangular microchannel
.
J. Colloid Interface Sci.
280
,
155
164
.
5.
Lee
J
;
Mudawar
I.
Two-phase flow in high-heat-flux micro-channel heat sink for refrigeration cooling applications: Part II-heat transfer characteristics
.
International Journal of Heat and Mass Transfer
,
48
(
2005
)
941
955
.
6.
Muller
R
;
Schmidt
P
;
Munding
A
;
Cronmaier
R
;
Kohn
E.
Elements for surface microfluidics in diamond
.
Diamond and Related Materials
,
13
(
2004
)
780
784
.
7.
Peles
YP
;
Yarin
LP
;
Hetsroni
G
,
2000
.
Thermohydrodynamic characteristics of two-phase flow in a heated capillary
.
International Journal of Multiphase Flow
,
26
,
1063
1093
.
8.
Sobhan
CB
;
Garimella
SV
.
Microscale Thermophysical Engineering
,
5
(
2001
)
293
311
.
9.
Zhang
L
;
Koo
JM
:
Jiang
K
;
Asheghi
M
;
Goodson
KE
;
Santiago
JG
; and
Kenny
TW
.
Measurements and Modeling of two-phase flow in microchannels with nearly constant heat flux boundary conditions
.
Journal of Electromechanical Systems
,
11
(
1
) (
2002
)
12
19
.
This content is only available via PDF.
You do not currently have access to this content.