Wireless communication has changed the world as it has opened up our ability to explore, record, and share information. However it is limited as it is dependent on a power source, such as a battery which has to be occasionally replaced. Researchers at the University of Washington though have developed a new wireless system that requires no power source in the connected devices.
Right now there are likely over a dozen different wireless signals passing through my body from Wi-Fi routers, cell towers, TV stations, radio stations, and more. All of these signals effectively put energy into thin air, which the Washington researchers are tapping into. Instead of creating devices that generate a signal, the researchers' devices instead reflect or fail to reflect already broadcasted signals, which also carry enough energy to power the devices. Even miles away from the original broadcast source, the researchers were able to build a network of devices feet apart.
As these devices require no power to operate, the researchers see them potentially being deployed as permanent sensor networks. Such networks could be tasked with monitoring a bridge's health, or could exist within homes to create a smart-house.
Source: University of Washington