Whether it is a T-shirt that can display changing messages or a carpet that can sense where you are standing, the future of smart textiles has often seemed rooted in science fiction. Now researchers say they have created smart fibres that can do exactly those things – and they do not even require a battery pack. Researchers in China say they have created fibre-based electronics that harness electromagnetic energy in the atmosphere, using the human body as part of the circuit. This makes a “body-coupled” fibre electronic technology that does…