Ever wondered about the source of that humming sound coming from your computer? It's most likely the fan that tries to ventilate the internal components. That's a typical cooling system.
I am not a rocket scientist, but generally speaking, as electronic components get tinier and more powerful, the amount of heat they generate gets proportionately higher. This is due to the simple fact that there's just not enough surface for the heat to dissipate quickly enough. That's why all computers' processors and high-end video cards come with a heat sink with a fan on top. Take this heat sink away and you'd fry the component in a matter of seconds.
Now bring these little advanced devices into space, where there's no air or moisture to help conduct the heat, and you'll have an even bigger challenge. And that's exactly what NASA has been facing.
According to NASA's Jeff Didion, a thermal engineer at the Goddard Space Flight Center, in the world of electronics, thermal control is always one of the limiting factors. He has been collaborating with Jamal Seyed-Yagoobi, a professor at the Illinois Institute of Technology in Chicago, to partner with the U.S. Air Force and National Renewable Energy Laboratory to find ways to push the envelope of thermal-control barriers.
The result is the new electrohydrodynamic (EHD)-based thermal control technology, unveiled yesterday, that promises to make it easier and more efficient to remove heat from small spaces. This solution is meant to address a particular challenge for engineers building advanced space instruments and microprocessors that could fail if the heat they generate is not removed.
The prototype of the new thermal control technology is a tiny pump, about the size of a little finger, which, apart from the cooling function, is designed to withstand the extreme launch loads as a rocket lifts off and hurtles toward space. The pump will be demonstrated in June on a rocket mission designed to carry microsatellites into space. "Should the device survive the vibration, the technology will have achieved a major milestone in its development," Didion said. "It will mean that it is at or near operational status, making it a viable technology for use on spaceflight instruments."
While the device is being called a pump, the prototype has no moving parts. According to Didion, unlike current cooling technologies used today by instrument and component developers, EHD does not rely on mechanical pumps and other moving parts. Instead, it uses electric fields to pump coolant through tiny ducts inside a thermal cold plate. From there, the waste heat is dumped onto a radiator and dispersed far from heat-sensitive circuitry that must operate within certain temperature ranges.
The fact that no mechanical parts are required means the new cooling system is lighter, consumes less power, (about .5W) and most importantly, can be scaled to different sizes, from larger cold plates to micro-scale electronic components and lab-on-a-chip devices. To see how this would work out, apart from the tiny pump to be tested in the rocket mission in June, a prototype EHD cold plate is also scheduled to be used as an experiment on the International Space Station in 2013.
In the meantime, Didion said, the team is continuing its work to further advance EHD, such as developing EHD pumps in microchannels that are etched onto silicon wafers. The next step is placing the technology on circuit boards, with the ultimate goal of scaling it to the chip level where the ducts would be no larger than 100 microns, or about the width of a human hair.
There's not yet any information available on how much the technology costs, but hopefully in the future, it will be applied to more down-to-earth applications, such as a computer's microprocessor. Then you wouldn't have to worry about getting a water-cooling system or a huge fan if you're big on overclocking.
After helping to develop polarized sunglasses and proliferate the use of Velcro, this just might be the next, coolest thing--quite literally--that NASA has had to offer.