Carbon Nanotubes: Electrical Conductivity We’ve Barely Begun to Use

While the legendary resistance of carbon nanotubes allows them to increase the strength of composite materials, their electrical conductivity makes them suitable for many other purposes as well! Raymor Industries Inc., a Quebec firm, produces single-wall carbon nanotubes, with its greatest sales volume going to Asia. These nanotubes will be incorporated into thin transparent layers whose properties will be enhanced: they will become conductive.

The entire microelectronics sector is looking for an effective solution for dissipating charges, in order to protect fragile electronic components from accidental electrical discharges that could impair their operation. A simple and practical solution is to coat the component (whether it’s a transistor, display screen or CCD array…) with a transparent conductive layer that will dissipate the charges much like a Faraday cage would do. Raymor’s single-wall carbon nanotubes have been shown to have all the properties needed to perform this delicate task, which is why they are on their way to being adopted by many foreign developers.

Another emerging application for carbon nanotubes is in the field of gas sensors. NanoSense, a California company specializing in chemical sensing and odorant detection, gets its supply of semiconducting carbon nanotubes from Raymor. These are functionalized and then deposited to form thin semiconducting layers integrated to a sensor, whose variation in conductivity will serve as an alert to the presence of a gas to be detected. This technology makes it possible to lower the detection threshold of some gases to less than 200 parts per billion (ppb).