Researchers Chill Down Fan-Cooled PCs Even More

Researchers at Purdue University and Intel have developed heat dissipation technology that can boost the performance of chip-cooling systems by up to 200 percent.

The researchers are developing ionic wind engines, devices that work with current air-cooling technologies like fans and heat sinks. The devices pass an electrical current to stir up stationary air molecules, leading to better air flow and dissipation of heat.

"To date, we have demonstrated that the technology can enhance fan cooling by more than 200 percent," said Suresh Garimella, professor at Purdue University, who is also a researcher on the project.

Current air cooling technology is attractive because of its cost advantages and ease of implementation, Garimella said. However, fans and heat sinks can't manage all the heat generated by chips.

Ionic Wind Technology
Ionic wind engines can be placed on a chip or a laptop to complement the current air-cooling technology to better manage heat dissipation, avoiding the need to switch to alternative, costlier cooling approaches like liquid cooling, Garimella said.

"The ionic wind technology we are developing is designed to work in addition to conventional fan-driven methods, not necessarily as a replacement for current systems," Garimella said.

Ionic winds are generated when electrically charged atoms stir up air molecules, which normally are stationary. When a current flows from a negatively charged electrode to a positively charged electrode, it collides with air molecules, producing positively charged ions that move back toward the negatively charged electrodes, creating an ionic wind. When the ionic wind gets the air molecules moving, the air flow on the chip surface increases, leading to better heat transfer and dissipation.

The engines are small enough to be fabricated on a chip or laptop and can be selectively placed depending on air flow, Garimella said. The researchers are trying to miniaturize the millimeter-scale devices to micron-scale dimensions.

Size reduction is just one problem facing researchers in putting the engines to practical use. Portable platforms pose a challenge as there is limited space for cooling systems, he said. Moreover, as chips become faster the amount of heat that needs to be removed increases, which increases the challenge to cool down a laptop and its surfaces, Garimella said.

"We are currently dealing with challenges to demonstrate the viability of the technology at the micro scale, and these must be overcome before the technology can be brought to market, at least for the chip-cooling arena," he said.

Garimella couldn't comment on when the technology will reach chips, but he noted some inherent advantages over alternatives like liquid cooling.

"Although liquid cooling typically provides higher heat removal rates, air cooling technologies are cheaper to implement and by using ionic wind engines, their cooling capacity can be enhanced," Garimella said.