Nanotube fibre production in a spin

light bulb

Bulb suspended by CNT fibres © Science/AAAS

No, that light bulb isn't floating in thin air, it's suspended by two 24μm thick fibres spun from carbon nanotubes (CNTs). An international collaboration led by Matteo Pasquali, at Rice University in the US, has developed a method of manufacturing high-performance CNT fibres using wet spinning.

Until now, the best performing CNT fibres have been manufactured in a solid state process that is not suited for scaling-up. Wet spinning, pulling a precipitate out of solution with a rotating spinneret, has been used previously but resulted in fibres with disappointing properties. It was suggested that this was because the CNTs were too short, but Pasquali's team have now shown that short CNTs are actually what you need. Their new fibres are spun using nanotubes that are approximately 5μm long.

The CNT fibres can be spun into lengths of 100–500μm long and are much stronger than previous wet-spun fibres and are of comparable strength to solid state manufactured fibres. When Pasquali's team doped their fibres with iodine they also beat their doped solid state competitors when it came to electrical conductivity, which is why the threads in the picture can not only suspend the bulb but also carry enough electricity to light it.

In their paper, Pasquali's team suggests that using shorter CNTs improved CNT–CNT stress transfer and lowered the defect density in the fibres, as the shorter CNTs can fit together better. However, even these improvements result in fibres with poorer properties when compared with single CNTs. The next step to improve their fibres, say the team, is to improve the manufacture and consistency of the CNTs that are used to make the fibres.

Related Content

Super-elastic wire stretches without losing power

23 July 2015 Research

news image

Fibre that can stretch 14 times its own length could find its way into robotic arms and satellites

Flexible polymer threads set to light up clothing

23 March 2015 Research

news image

Multi-colour light-emitting wires can be woven or knitted into fabrics for haute couture or monitoring patients' vital signs

Most Commented

How do we solve a problem like Marie?

21 May 2015 The Crucible

news image

Women in science’s history deserve better treatment than myths and martyrdom, says Philip Ball

Chemistry at heart of VW emissions cheating

28 September 2015 News and Analysis

news image

Car firm dodged nitrogen oxide pollution limits using software that detected testing