Scientists have made a huge breakthrough that allows them to convert radio signals into power. The discovery could allow phones and other devices to function without batteries. Scientists in the US developed the device, known as a "rectenna", from a semiconductor just a few atoms thick. Wi-fi signals captured by an integrated antenna are transformed into a current suitable for electronic circuits. The device could be used to provide battery-less power for smartphones, laptops, medical devices, and wearable technology, according to the US-led team. This has major implications for the future of "electronic intelligence", according to scientists. For his part, Professor Tomas Palacios, director of the Massachusetts Institute of Technology and Microsystems Technology Laboratories Center: "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?" the Independent newspaper reported. "We have come up with a new way to power the electronics systems of the future, by harvesting wi-fi energy in a way thats easily integrated into large areas, to bring intelligence to every object around us," he added. In experiments, the rectenna generated about 40 microwatts of power when exposed to typical wi-fi signals of around 150 microwatts. That is more than enough to light up a simple mobile display or activates silicon chips. The research is published in the latest online issue of the journal Nature. Spanish co-author Professor Jesus Grajal, from the Technical University of Madrid, said a key application could be in the field of medical implants and "pills" that stream health data after being swallowed by patients.