Scientists have recently discovered that they can convert radio signals into power, which could allow phone and other devices to work without batteries.
US scientists developed a device called “rectenna” using semiconductors that are just a few atoms thick. They are able to capture Wi-Fi signals, which they transform into a DC current suitable for electronic circuits.
Professor Tomas Palacios, director of the Massachusetts Institute of Technology and Microsystems Technology Laboratories Centre for Graphene Devices and 2D Systems, said: "What if we could develop electronic systems that we wrap around a bridge or cover an entire highway, or the walls of our office and bring electronic intelligence to everything around us? How do you provide energy for those electronics?"