  The paper presents numerical results on an innovative concept of an
efficient, site-specific cooling technology for microprocessor hot spots using
Alternating Current Electrothermal Flow (ACET). ACET deploys an electrokinetic
transport mechanism without requiring any external prime mover and can be shown
to be highly effective in reducing hot spot temperatures below their allowable
limits. The proposed technique leverages the heat source(s) itself to drive the
fluid in the ACET cooling mechanism, thereby making this a highly energy
efficient active technique. Our parametric analyses present the optimal range
of fluid properties, viz. electrical conductivity where the cooling efficiency
is maximum. Further, the impact of geometrical parameters as well as input
voltages has been characterized. Our results show a reduction of hot spot
temperature by more than 30% for flow through a channel of 600 microns under
appropriate conditions at an applied AC voltage of 10-12 V. Comparison with
other micro-cooler technologies show the proposed technique to be more energy
efficient in its range of operation. These results establish the potential of
the ACET cooling and can open up a new avenue to be explored for thermal
management of miniaturized devices and systems.
