A better shield

University of Virginia engineering professor Mool C. Gupta and his team have used carbon nanotubes to unite the virtues of plastics and metals in a new ultra-lightweight, conductive material that may revolutionise electromagnetic shielding.

Sensitive electronic devices like cell phones and computers require shielding from electromagnetic interference (EMI). Such shielding - which must be electrically conductive - has traditionally been made of metal, which poses a weight problem in the push to miniaturise and lighten electronics. In response, Gupta led a team that has developed an ultra-lightweight nanocomposite that outperforms conventional shielding.

This new nanocomposite material is a mixture of plastic, carbon nanotubes and a foaming agent, making it extremely lightweight, corrosion-proof and cheaper to produce than metal. The carbon nanotubes play a key role in creating these unique properties, explained Gupta.

Most notably, experiments revealed that only 1 percent to 2 percent of the material's composition needed to be comprised of nanotubes to increase the electrical conductivity by 10 orders of magnitude. The addition of carbon nanotubes also increased the material's thermal conductivity, improving its capacity to dissipate heat.