MAY 2019 I DESIGN007 MAGAZINE 69
ly, therefore offering exceptionally low thermal
resistance. With phase-change technology, a
key benefit is the greatly reduced effects of
pump out, making phase-change materials an
excellent choice for applications that undergo
widely varying temperatures.
With thermal management playing more and
more of a crucial role in electronics, it is like-
ly that the stability of these new phase-change
materials will see them take an overwhelming
lead in thermal management technology. And
as this technology rapidly develops, this will
take effect sooner rather than later.
DESIGN007
References
1. "Electrolube Addresses Major Market Changes to
Thermal Management of LEDs," SMT007 Online.
Jade Bridges is global technical
support manager at Electrolube.
To read past columns from
Electrolube, click here. Also,
visit I-007eBooks.com to
download your copy of Electrol-
ube's book,
The Printed Circuit
Assembler's Guide to… Conformal Coatings for Harsh
Environments, as well as other free, educational titles.
In the nanoscale gaps, thermal radiation between ob-
jects increases greatly with closer distances. The amount
of heat transfer in this scale was found to be from 1,000
to 10,000 times greater than the blackbody radiation heat
transfer, which was once considered the theoretical max-
imum for the rate of thermal radiation. This phenomenon
is called near-field thermal radiation. With recent devel-
opments in nanotechnology, research into near-field ther-
mal radiation between various materials has been active-
ly carried out.
Surface polariton coupling generated from nanostruc-
tures has been of particular interest because it enhances
the amount of near-field thermal radiation between two
objects, and allows the spectral control of near-field ther-
mal radiation. This advantage has motivated much of the
recent theoretical research on the application of near-
field thermal radiation using nanostructures such as thin
films, multilayer nanostructures, and nanowires. Thus far,
most of the studies have focused on measuring near-field
thermal radiation between isotropic materials.
A joint team led by Professor Bong Jae Lee and Pro-
fessor Seung Seob Lee from the department of mechan-
ical engineering at KAIST succeeded in measuring near-
field thermal radiation according to the vacuum distance
between metallo-dielectric (MD) multilayer nanostruc-
tures by using a custom MEMS (microelectromechanical
systems) device integrated platform with a three-axis
nanopositioner.
By measuring the near-field thermal radiation with a
varying number of unit cells and the fill factor of the mul-
tilayer nanostructures, the team demon-
strated that the surface plasmon polari-
ton coupling enhances near-field thermal
radiation greatly and allows spectral con-
trol over the heat transfer.
The researcher's thermal radiation
control technology can be applied to
next-generation semiconductor packag-
ing, thermophotovoltaic cells, and ther-
mal management systems. It also has the
potential to be applied to a sustainable
energy source for IoT sensors.
This research, led by Ph.D. Mikyung Lim
and Ph.D. candidate Jaeman Song, was
published in Nature Communications.
(Source: KAIST)
KAIST Technology Controls Near-field Thermal Radiation
