Scientists at Stanford University have released new findings that demonstrate the benefits of using carbon nanotube arrays at critical junctions between two materials to help better relieve thermal stress.
Thermal stress, often caused by the joining of two materials that expand and contract at different rates as temperatures change, can lead to unnecessary strain and component damage if not mitigated properly.
“Think about the heat sink for a microprocessor,” senior research paper author Kenneth Goodson, professor and Bosch Chairmain of Mechanical Engineering at Stanford University, said. “It is exposed to high heat fluxes for long periods of time, and repeated instances of heating and cooling.”
Currently, materials such as solder and gels are used to help prevent such damage; however, as increasingly powerful but smaller electronic devices require more electrical power to be pushed through smaller circuits, the potential for failure at these critical junctions continues to grow.
Now, research conducted by researchers at Stanford University indicate that longer carbon nanotube structures (CNTs), grown less-densely together, seemed to have the best combination of flexibility, heat conductivity and strength for use in electronics and other industrial applications where thermal stress is expected. The team employed a number of experiments to determine the best growth parameters to achieve optimum thermal conductivity, as well as computer simulations to examine the manner in which van der Waals forces influence the behavior of CNTs. Their findings are published in the Proceedings of the National Academy of Sciences (PNAS).
“When you hear about nanotechnology, it’s usually about the superlatives, the strongest this, the thinnest,” Goodson said. “But we think the answers will lie in finding the right combinations of properties, something that’s strong and conducts heat like a metal but can flex and bend as well.”
