Sensors and microcomputers have become part of our life. We use them everywhere like Bluetooth communication, internet wireless, water sensor, etc. All of which require source of power. While putting a battery onboard the device is one solution, but from time to time it needs to be replaced or recharged. Engineers at the University of Washington (UW) could help to do away with the need for a battery for some wireless devices altogether.
The team at UW has developed a technique called "ambient backscatter", which can let devices use the cellular and TV transmissions already being broadcast around us, reflecting those signals to send and receive their own data to similar devices, without the need for a battery or other power source.
“We can repurpose wireless signals that are already around us into both a source of power and a communication medium. It’s hopefully going to have applications in a number of areas including wearable computing, smart homes and self-sustaining sensor networks.” - Shyam Gollakota, lead researcher and UW assistant professor of computer science and engineering.
“Our devices form a network out of thin air. You can reflect these signals slightly to create a Morse code of communication between battery-free devices.” - Joshua Smith, co-author and a UW associate professor of computer science and engineering and of electrical engineering
Researchers set up a small testing network in Seattle, and the devices were able to communicate with each other, as sensors would in a real-world application, even up to 6.5 miles away from a TV tower.
Ambient backscatter technology is suitable in vast applications, like enabling cellphones to send text messages while the battery were to die; embedding sensor into bridges, tunnels, subways, etc., for real-time monitoring of the conditions or integrity of the structures, without requiring a remote power source.