Engineers at Oregon State Univ. have invented a new technology for less costly production of microchannel arrays, which are thin layers of metal stacked together. Credit: Oregon State Univ. |
Engineers at Oregon State Univ. have invented a new way to
use surface-mount adhesives in the production of low-temperature, microchannel
heat exchangers—an advance that will make this promising technology much less
expensive for many commercial applications.
This type of technology will be needed, researchers say, in
next-generation computers, lasers, consumer electronics, automobile cooling
systems, fuel processors, miniature heat pumps, and more.
New industries and jobs are possible. A patent has been
applied for, the findings reported in the Journal
of Manufacturing Processes, and the university is seeking a partner for
further commercial development.
“Even though microchannel arrays have enormous potential for
more efficient heat transfer and chemical reactions, high production costs have
so far held back the broad, mainstream use of the technology,” said Brian Paul,
a professor in the OSU School of Mechanical, Industrial and Manufacturing
Engineering.
“In certain applications, this new approach has reduced
material costs by 50%,” Paul said. “It could cut production bonding costs by
more than 90%, compared to existing approaches to microchannel lamination. And
the use of surface-mount adhesives is directly translatable to the electronics
assembly industry, so there is less risk going to market.”
“This type of manufacturing research could enable a
microchannel revolution,” he said.
Microchannels, the diameter of a human hair, can be
patterned into the surface of a metal or plastic, and can be designed to speed
up the heat exchange between fluids, or the mixing and separation of fluids
during chemical reactions. The accelerated heat and mass transfer leads to
smaller heat exchangers and chemical reactors and separators, such as a
portable “home dialysis” system that evolved out of previous OSU research.
Cost and production issues, however, have until now
constrained the wider industrial use of this technology. The new manufacturing
technique developed at OSU should help change that.
“We have demonstrated the use of surface-mount adhesives to
create microchannels on a wide variety of metals, including aluminum, which is
very cheap,” said Prawin Paulraj, an OSU doctoral candidate and lead author on
the recent study. “Bonding aluminum is difficult with conventional techniques.”
These very thin pieces of patterned metal—akin to aluminum
foil—can be bonded one on top of another to increase the number of
microchannels in a heat exchanger, and the amount of fluid that can be
processed. Creation of laminated microchannel arrays in a wide variety of materials
is possible, including aluminum, copper, titanium, stainless steel, and other
metals.
“In computers and electronics, the heat generated by the
electrical circuit is a limiting factor in how small you can make it,” Paulraj
said. “Microchannel process technology provides an efficient way to cool
computers and consumer electronics, and make them even smaller.”
The adhesives are limited in temperature to about that of
boiling water. The researchers say that possible uses might include radiators
to cool an automobile engine or small, very efficient heat pumps for efficient
air conditioning within buildings.
