EPFL researchers have developed conductive tracks that can be bent and stretched up to four times their original length, and they can be stretched a million times without cracking or interrupting their conductivity. 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.