Getting rid of heat is one of the main problems that microprocessor designers face. Building a fast and powerful processor often comes with a slew of thermal transport problems that are both difficult and expensive to solve. However, a new study may provide a novel and effective method of cooling these increasingly powerful microprocessors. A team of researchers from the Lawrence Berkeley National Laboratory have teamed up with Intel engineers to come up with an effective thermal transport method using carbon nanotubes.
The Department of Energy-run lab may have come up with a way to cool microprocessors using carbon nanotubes bonded to metal surfaces using organic molecules. The organic molecules were used to form a covalent bond between metal and carbon nanotube resulting in a thermal transport mechanism that offers a radical increase in heat transfer efficiency. Since the covalent bonds between the carbon nanotubes and metal surfaces are formed using a low temperature process, the process can also be applied to microprocessors without damaging the sensitive circuits of these tiny computing powerhouses.
"We've developed covalent bond pathways that work for oxide-forming metals, such as aluminum and silicon, and for more noble metals, such as gold and copper," says Berkeley Lab physicist Frank Ogletree in a press release. "In both cases the mechanical adhesion improved so that surface bonds were strong enough to pull a carbon nanotube array off of its growth substrate and significantly improve the transport of heat across the interface."
Due to the fact that carbon nanotubes are some of the most efficient heat conductors in existence, the study may highlight future applications for the material.
"The thermal conductivity of carbon nanotubes exceeds that of diamond or any other natural material but because carbon nanotubes are so chemically stable, their chemical interactions with most other materials are relatively weak, which makes for high thermal interface resistance," says Ogletree.
Ogletree and his colleagues Sumanjeet Kaur, Nachiket Raravikar, Brett Helms and Ravi Prasher published the paper ""Enhanced Thermal Transport at Covalently Functionalized Carbon Nanotube Array Interfaces" in online journal Nature Communications. The study has also caught the interest of microprocessor manufacturers such as Intel, which has already visited the Microfoundry during the course of the study.
"Intel came to the Molecular Foundry wanting to improve the performance of carbon nanotubes in devices. Working with Nachiket Raravikar and Ravi Prasher, who were both Intel engineers when the project was initiated, we were able to increase and strengthen the contact between carbon nanotubes and the surfaces of other materials. This reduces thermal resistance and substantially improves heat transport efficiency."
