Keeping cool and staying hot

This nanoscale-level coating of zinc oxide on top of a copper plate holds the potential to dramatically increase heat transfer characteristics and lead to a revolution in heating and cooling technology, according to experts at Oregon State University and the Pacific Northwest National Laboratory. (Photo courtesy of Oregon State University)

Researchers at Oregon State University and the Pacific Northwest National Laboratory have discovered a new way to apply nanostructure coatings to make heat transfer far more efficient, with important potential applications to high tech devices as well as the conventional heating and cooling industry.

These coatings can remove heat four times faster than the same materials before they are coated, using inexpensive materials and application procedures.

The discovery has the potential to revolutionize cooling technology, experts say.

The findings have just been announced in the International Journal of Heat and Mass Transfer, and a patent application has been filed.

"For the configurations we investigated, this approach achieves heat transfer approaching theoretical maximums," said Terry Hendricks, the project leader from the Pacific Northwest National Laboratory. "This is quite significant."

The improvement in heat transfer achieved by modifying surfaces at the nanoscale has possible applications in both micro- and macro-scale industrial systems, researchers said. The coatings produced a "heat transfer coefficient" 10 times higher than uncoated surfaces.

Heat exchange has been a significant issue in many mechanical devices since the Industrial Revolution.

The radiator and circulating water in an automobile engine exist to address this problem. Heat exchangers are what make modern air conditioners or refrigerators function, and inadequate cooling is a limiting factor for many advanced technology applications, ranging from laptop computers to advanced radar systems.

"Many electronic devices need to remove a lot of heat quickly, and that’s always been difficult to do," said Chih-hung Chang, an associate professor in the School of Chemical, Biological and Environmental Engineering at Oregon State University. "This combination of a nanostructure on top of a microstructure has the potential for heat transfer that’s much more efficient than anything we’ve had before."