Japanese scientists create elastic electric wires

Japanese scientists have developed an elastic material that conducts electricity, according to local press reports.

The material may have applications in a variety of fields, including so-called wearable computing devices and for applications where mechanical stress on components creates a need for greater durability.

The new material can be stretched to more than twice its original length in some applications. It is more than 500 times as conductive as most existing flexible conductors, such as conductive rubber, which conducts electricity too poorly for many purposes.

The black rubber-like elastic conductor is made of carbon nanotubes set in an elastic resin. It was developed by a team led by Takeo Someya at the University of Tokyo's School of Engineering.

The team's key breakthrough was discovering how to dissolve the resin in an ionic liquid that allows the carbon nanotubes to spread out evenly, Someya said.

The two to four millimetre-long nanotubes apparently become entangled so that conductivity is maintained as the material is stretched, he said.

"Non-elastic materials have a risk of breakage when they are hit by a pointed object, etc, even if they are bendable," Someya told Nikkei Electronics.

"For flexible devices, elasticity is a very important factor."

The newly-developed material can be stretched up to 38 per cent when it is the form of individual fibres. However, by weaving the strands into a mesh, it can be stretched by as much as 123 per cent beyond its original length as the mesh deforms.