Chip cooling: The answer is blowing in the wind

Posted by Rick C. Hodgin

West Lafayette (IN) - Researchers at Purdue University have developed a leapfrog way to achieve better chip cooling. This apparently promising new solution more than doubles the air-based heat removal solutions seen in laptops and other small appliances today, paving the way for faster and more powerful consumer products. Desktops and mobile cooling solutions based on this technology could debut as early as 2010.

Called “Ionic Wind,” this new solution addresses one of the biggest bottlenecks in forced air heat removal technologies: The “no-slip effect”, which refers to a scenario in which air molecules near the surface of a metal are nearly stationary, making them difficult to blow away. The further out the molecules are from the surface, the more easily they move about. While this allows those more distant molecules to be blown, the ones closer to the metal act as insulators keeping the heat inside.

Purdue's new technique breaks down that insulation barrier and creates thousands of tiny hurricanes. Once the hurricanes begin moving air around, the heat can be blown away.

This hurricane effect is achieved by using a combination of anodes and cathodes arranged in a particular way and spaced about 10 mm apart. When a voltage is applied, ion jets are created and ejected from the nodes. When this happens, the normally stationary surface air begins to move in tiny vortexes. Once pulled away from the surface by the vortex, cooler air is brought in behind to fill in the void. The metal gives off its heat to the cooler air which is then, in turn, also ejected by another vortex. This effect yields the greater heat exchange efficiency seen in this solution.

According to Purdue scientists, infrared tests have shown a mock CPU using the new cooling technique reduced temperatures from 60 degrees Celsius to 35 degrees Celsius.
 

 
The research team said it still has work to do on this project as the prototypes are very fragile. In order to make this technology ready for consumer applications, it has to be made much more durable and easy to install. According to Suresh Garimella, a professor of mechanical engineering working on the project at Purdue, all mechanical problems will be sorted out within a year.

Research for this project was funded by Intel and patents are currently pending.