Microcombing technique improves electrical conductivity and strength of CNT films

The technique is also claimed to improve the electrical conductivity that makes these films attractive for use in electronic and aerospace applications.

“It’s a simple process and can create a lightweight CNT film, or ‘bucky paper,’ that is a meter wide and twice as strong as previous such films – it’s even stronger than CNT fibers,” said Yuntian Zhu, Distinguished Professor of Materials Science and Engineering at NC State and corresponding author of a paper describing the work.

According to NC State, the researchers begin by growing the CNTs on a conventional substrate in a closely packed array. The CNTs are tangled together, so when researchers pull on one end of the array the CNTs form a continuous ribbon that is nanometers thick. This ribbon is attached to a spool, which begins winding the ribbon up.

As the spool pulls, the CNT ribbon is dragged between two surgical blades, which have micrometer-scale fissures on their cutting edge. These fissures are said to create a kind of “microcomb” that pulls the CNTs into alignment.