Ah, graphene. Not a week goes by where we don’t hear news about how its unique properties could revolutionize electronics. This week, it’s all about finding new ways to keep our favorite devices cooler.
I could use it. My poor iPad and iPhone heat up quite a bit with the abuse I put them through.
In 2D, hexagonal boron nitride looks just like graphene. It’s also a great conductor of heat. A property the researchers from Rice wanted to investigate in 3D arrangements.
Rice’s Rouzbeh Shahsavari explains how controlling heat flow works in today’s devices.
“Typically in all electronics, it is highly desired to get heat out of the system as quickly and efficiently as possible,” Shahsavari said. “One of the drawbacks in electronics, especially when you have layered materials on a substrate, is that heat moves very quickly in one direction, along a conductive plane, but not so good from layer to layer. Multiple stacked graphene layers is a good example of this.”
Shahsavari and his colleague Navid Sakhavand conducted simulations to see how 3D boron nitride could control heat flow. Instead of moving the heat in just one direction, the simulations showed the 3D structures of white graphene could move heat in all directions.
Image credit: Rice University. Shahsavari (left) and Sakhavand (right)
The researchers also found the length and density of interconnecting tubes could control heat flow. Shorter ones slowed heat conduction while longer ones speed it up.
“This type of 3-D thermal-management system can open up opportunities for thermal switches, or thermal rectifiers, where the heat flowing in one direction can be different than the reverse direction,” Shahsavari said. “This can be done by changing the shape of the material, or changing its mass – say one side is heavier than the other – to create a switch. The heat would always prefer to go one way, but in the reverse direction it would be slower.”
This research continues to show how graphene could lead to smaller, cooler and more powerful electronic devices.
Graphene remains one of the most promising materials out there. The proposed uses for the material are nearly limitless. Now, if we can just figure out how to produce it on a scale that can be used commercially.