Carbon nanotubes could replace copper as heat dissipating material in electronics, researchers say

Troy (NY) - Heatsinks are essential in many electronics devices, including computer systems, to dissipate heat that is generate from various kinds of chips. Researchers from the Rensselaer Polytechnic Institute and the University of Oulu in Finland have developed a heatsink from carbon nanotubes, which they claims is as efficient as copper, but much more durable as chips get smaller and smaller.

To create the heatsink, the researchers have grown films consisting of 1.2 millimeter long multi-walled carbon nanotubes. A laser was used to carve out freestanding 10x10 fin array mini-heatsinks, which were soldered of a thermometer test chip.

Compared to a chip with no cooling source, 11% more power was dissipated from the chip mounted with the nanotube cooler, the researchers said. Under forced nitrogen flow, the cooling performance with the fins was improved by 19%. The results were reason enough for the project team to believe that the carbon nanotube heatsink carries the potential of a "lightweight, solid-state add-on structure for an on-chip thermal management scheme."

Copper heatsinks are common today and copper is generally considered the most efficient heat dissipating material - from a perspective of both performance and cost. However, with semiconductors shrinking at an accelerating pace, copper could become less of an option : According to Robert Vajtai, a researcher with the Rensselaer Nanotechnology Center, the integrity of copper "breaks down" in structures that are reduced to sub-millimeter sizes. "Silicon becomes very brittle and easily shatters, while metallic structures become bendable and weak," he said. In contrast, he said that "nanotubes are more flexible, resilient, and 10 times lighter than any other cooling material available."