Researchers optimise nanotube arrays for thermally stressed applications

Researcher Yoonjin Won used a variety of techniques to assemble nanotubes with different structural characteristics and then measured their flexibility and thermal conductivity. Working with collaborators at the University of Tokyo, Won created nanotubes that grew relatively straight, although with some degree of entanglement. Won's experiments showed that longer nanotubes, grown less densely, had the best combination of flexibility and strength for use in electronics and other industrial applications where thermal stress is expected. The experimental results, along with a computer simulation, are said to reinforce the findings that longer, less entangled nanotubes would offer the best mixture of the desired characteristics strength, flexibility and heat transfer. However, van der Waals forces between the carbon nanotubes mean some bending and irregularity will be inevitable. "When you hear about nanotechnology it's usually about the superlatives: the strongest this, the thinnest that," said Professor Kenneth Goodson said. "But we think the answers will lie in finding unique combinations of properties; in this case, something that's strong and conducts heat like a metal, but can flex and bend as well."