In the not too distant "Internet of Things" reality, sensors could be embedded in everyday objects to help monitor and track everything from the safety of bridges to the health of your heart. But what’s holding this new reality back is having a way to inexpensively power and connect these devices to the Internet, say engineers at the University of Washington, Seattle.
They say that they have designed a new communication system that uses radio frequency signals as a power source and reuses existing Wi-Fi infrastructure to provide Internet connectivity to these devices. Called Wi-Fi backscatter, this technology is the first that can connect battery-free devices to Wi-Fi infrastructure while consuming orders of magnitude less power than what Wi-Fi typically requires.
Their work builds upon previous research that showed how low-powered devices such as temperature sensors or wearable technology could run without batteries by harnessing energy from existing radio, TV, and wireless signals in the air. This new project goes further by connecting each individual device to the Internet, which previously wasn't possible.
The university’s Wi-Fi backscatter tag has communicated with a Wi-Fi device at rates of 1 kilobit per second with about 2 meters between the devices. They plan to extend the range to about 20 meters and have patents filed on the technology.