Researchers from the University of Washington and Delft University of Technology have developed a new gadget that doesn’t need a battery or any external power source to keep it powered. The WISP is a combination sensor and computing chip that uses a standard off-the-shelf RFID reader to suck in radio waves and convert them into electricity. With the help of Wisent, the device can be programmed wirelessly and uses the very same radio waves to communicate. The discovery could highly transform the Internet of Things (IoT) world.
Source: https://thehackernews.com/2016/04/radio-wireless-power.html