6 - Kuwait Oil Company

A research team at Singapore’s Nanyang Technological University (NTU) has
successfully used a laser to cool down a semiconductor material known as Cadmium
Sulfide. The results of the recently published study could lead to the development
of self-cooling computer chips and smaller, more energy efficient air conditioners
and refrigerators that don't produce greenhouse gases. Cadmium Sulfide, an
inorganic compound, is a type of group II-IV semiconductor commonly used in
pigments to form the color yellow. It is also used as a thin-film layer in solar cells,
sensors and electronics. Led by Assistant Professor Xiong Qihua from the School
of Physical and Mathematical Sciences and the School of Electrical and Electronic
Engineering, the research team optically-refrigerated the compound from 20° C
(68° F) down to -20° C (-4° F). The potential for using semiconductors as the basis
for cooling structures powered by light could have some very usable permutations
in the real world. Currently, high-powered devices such as Magnetic Resonance
Imagers (MRIs), night-vision goggles, satellite cameras, and even air-conditioning
systems and refrigerators all have one thing in common: they have bulky, noisy,
highly mechanical or complex cooling systems. These systems consume large
amounts of power and – in the case of refrigerants especially – often release harmful
greenhouse gases into the atmosphere. The breakthrough in laser cooling (aka
optical refrigeration) technology could lead to compact, cost effective, vibrationfree
and cryogen-less cooling systems in many different applications. CPUs could
reduce their reliance on external cooling systems like fans and incorporate built-in
laser controlled systems instead. The potential for minimized heat and prolonged
battery life in items such as tablets and smartphones is another example.
Breakthrough
Laser
Cooling
System Could
Save Space
and Energy
Printing three dimensional objects with incredibly fine details is now possible using
"two-photon lithography." With this technology, tiny structures on a nanometer scale
can be fabricated. Researchers at the Vienna University of Technology (TU Vienna)
have now made a major breakthrough in speeding up this printing technique: The
high-precision-3D-printer at TU Vienna is orders of magnitude faster than similar
devices. This opens up completely new areas of application, such as in medicine. The
3D printer uses a liquid resin, which is hardened at precisely the correct spots by a
focused laser beam. The focal point of the laser beam is guided through the resin by
movable mirrors and leaves behind a polymerized line of solid polymer, just a few
hundred nanometers wide. This high resolution enables the creation of intricately
structured sculptures as tiny as a grain of sand. “Until now, this technique used to be
quite slow,” says Professor Jürgen Stampfl from the Institute of Materials Science and
Technology at the TU Vienna. “The printing speed used to be measured in millimeters
per second – our device can do five meters in one second.” In two-photon lithography,
this is a world record. Researchers all over the world are working on 3D printers
today – at universities as well as in industry. Because of the dramatically increased
speed, much larger objects can now be created in a given period of time. This makes
two-photon-lithography an interesting technique for industry. At the TU Vienna,
scientists are now developing bio-compatible resins for medical applications. They
can be used to create scaffolds to which living cells can attach themselves facilitating
the systematic creation of biological tissues. The 3D printer could also be used to
create tailor made construction parts for biomedical technology or nanotechnology.
3D-Printer
with Nano-
Precision
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