As electronic components get smaller, the heat generated by the increasing power of these chips has increased the need for chip-cooling solutions.
Researchers at Rutgers University have developed a way to cool tiny chips with a combination of graphene and boron nitride crystal substrate.
“You can fit graphene, a very thin, two-dimensional material that can be miniaturized, to cool a hot spot that creates heating problems in your chip,” said Eva Andrei, Board of Governors professor of physics in the Department of Physics and Astronomy at Rutgers. “This solution doesn’t have moving parts and it’s quite efficient for cooling.”
Rutgers said it was able to achieve a power factor—the effectiveness of active cooling—two times higher than previous thermoelectric coolers.
The benefits of graphene are vast—it has only one-atom-thick layer and the thinnest flakes consist of carbon atoms arranged in honeycomb lattice that looks like chicken wire. It conducts electricity better than copper and is 100 times stronger than steel while having the ability to quickly diffuse heat.
In silicon dioxide—the traditional base for electronic chips—the material hinders performance because it scatters electronics that can carry heat away. In devices such as smartphones or computers, billions of transistors generate a considerable amount of heat. Because this heat hampers performance, the need for cooling is a must.
How They Did It
Current cooling methods include the use of little fans or water cooling, but both are bulky methods that can either break down or leak harming computers and other electronics.
“In a refrigerator, you have compression that does the cooling and you circulate a liquid,” Andrei said. “But this involves moving parts and one method of cooling without moving parts is called thermoelectric cooling.”
In electronics, thermoelectric cooling involves connecting a piece of wire, such as copper, to a hot chip and the heat is carried away passively. If the metal has both hot and cold ends, the metal’s atoms and electronics zip around the hot end and are sluggish at the cold end. Rutgers researchers applied voltage to the metal, sending a current from the hot end to the cold end, carrying away heat much more efficiently than via passive cooling.
Graphene is superior in both its passive and active cooling capability, making the material an excellent cooler.
“The electronics industry is moving towards this kind of cooling,” Andrei said. “There’s a very big research push to incorporate these kinds of coolers. There is a good chance that the graphene cooler is going to win out. Other materials out there are much more expensive, they’re not as thin and they don’t have such a high-power factor.”