Ambient Backscatter Devices (IMAGE) University of Washington Caption Using ambient backscatter, these devices can interact with users and communicate with each other without using batteries. They exchange information by reflecting or absorbing pre-existing radio signals. Credit University of Washington Usage Restrictions Photo credit required. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.