Nanowick at heart of new system to cool ‘power electronics’
Researchers have shown that an advanced cooling technology being developed for high-power electronics in military and automotive systems is capable of handling roughly 10 times the heat generated by conventional computer chips.
The miniature, lightweight device uses tiny copper spheres and carbon nanotubes to passively wick a coolant toward hot electronics, according to Suresh Garimella, the R. Eugene and Susie E. Goodson Distinguished Professor of Mechanical Engineering.
This wicking technology represents the heart of a new ultrathin “thermal ground plane,” a flat, hollow plate containing water. Similar “heat pipes” have been in use for more than two decades and are found in laptop computers. However, they are limited to cooling about 50 watts per square centimeter, which is good enough for standard computer chips but not for “power electronics” in military weapons systems and hybrid and electric vehicles, Garimella says.
The new type of cooling system can be used to prevent overheating of devices called insulated gate bipolar transistors which are high-power switching transistors used in hybrid and electric vehicles. The chips are required to drive electric motors, switching large amounts of power from the battery pack to electrical coils needed to accelerate a vehicle from zero to 60 mph in 10 seconds or less.
Potential military applications include advanced systems such as radar, lasers and electronics in aircraft and vehicles. The chips used in the automotive and military applications generate 300 watts per square centimeter or more.