Stretchable electronic films could revolutionise wearable devices

London: Researchers have developed electronic films that can be bent and stretched up to four times their original length.

The researchers believe that the new films that are almost as flexible as rubber could be used in artificial skin, connected clothing and on-body sensors.

The invention was described in the journal Advanced Materials.

Both solid and flexible, this new metallic and partially liquid film offers a wide range of possible applications. 

It could be used to make circuits that can be twisted and stretched -- ideal for artificial skin on prosthetics or robotic machines. 

It could also be integrated into fabric and used in connected clothing. 

And because it follows the shape and movements of the human body, it could be used for sensors designed to monitor particular biological functions.

"We can come up with all sorts of uses, in forms that are complex, moving or that change over time," said one of the study authors Hadrien Michaud from Swiss Federal Institute of Technology in Lausanne (EPFL) in Switzerland.

To develop the stretchable electronics the researchers used an alloy of gold and gallium. 

"Not only does gallium possess good electrical properties, but it also has a low melting point, around 30 degree Celsius," Study co-author Arthur Hirsch from EPFL said.

"So it melts in your hand, and, thanks to the process known as supercooling, it remains liquid at room temperature, even lower," Hirsch noted.

The layer of gold ensures the gallium remains homogeneous, preventing it from separating into droplets when it comes into contact with the polymer, the researchers explained.