Tiny fans to cool electronics

Research engineers at Purdue University are developing tiny, quiet fans that wiggle back and forth to help cool future laptop computers and other portable electronic gear.

The devices remove heat by waving a small blade in alternate directions. They consume only 1/150th as much electricity as conventional fans, and they have no gears or bearings, which produce friction and heat.

Because the fans work without motors that contain magnets, they do not produce electromagnetic noise that can interfere with electronic signals in computer circuits, said Suresh Garimella, an associate professor of mechanical engineering at Purdue.

The cramped interiors of laptop computers and cell phones contain empty spaces that are too small to house conventional fans but large enough to accommodate the new fans, some of which have blades about an inch long. Placing the fans in these previously empty spaces has been shown to dramatically reduce the interior temperatures of laptop computers.

The innovative fans will not replace conventional fans. Instead, they will be used to enhance the cooling now provided by conventional fans and passive design features, such as heat-dissipating fins.

In experiments on laptop computers, the Purdue researchers reduced the interior temperatures by as much as 8 degrees Celsius, Garimella said.