Due to its high thermal conductivity, graphene film has the potential to replace more widely used materials, such as copper and aluminum, for cooling electronic components. This is especially true as companies squeeze smaller and faster circuitry into chips.
Now, a research team from the Chalmers University of Technology in Sweden has developed a method for vastly increasing the cooling properties of graphene-based film, allowing it to more effectively dissipate heat from electronic devices.
The thermal conductivity of graphene-based film can be enhanced by pasting together several layers of the carbon-derived material. But until recently, the number of layers that could be linked, without falling apart, was too low to remove large amounts of heat. By developing a stronger bond between the graphene film and silicon component, the research team was able to increase the thickness of the material.
The research team reported that the graphene-based film could now be made with a thickness of 20 micrometers and a thermal conductivity of 1600 W/mk. This is more than four times the thermal conductivity of copper and almost seven times that of aluminum — two of the most commonly used materials in electronic heat sinks.
The research team achieved a higher thermal conductivity by using a process called functionalization, which involves the addition of a property-altering molecule to the material. When heated and put through hydrolysis, the molecule creates silane bonds between the graphene and the electronic component.
The research team noted that such high thermal conductivity would enable graphene film to be used in small, high-power applications, including light-emitting diodes, and radio frequency components. These devices would also be more energy efficient, as less energy will have to be used for cooling purposes. Recent studies have found that almost half the energy required to run computer servers is used for cooling purposes.
But graphene film is still being studied and still not widely used in electronic devices. In 2012, the graphene market only earned revenues of $9 million. But a recent report from research firm IDTechEx estimates that the market will earn revenues of nearly $200 million by 2025. The material is increasingly being used in lithium-ion battery anodes and in chips as an alternative to silicon.
