Power Source (image) Duke University Caption This small copper coil created the electromagnetic field by running an alternating electric current through it. In the background is the metamaterial "superlens" that focused the electromagnetic field onto another identically sized copper coil on the other side, which greatly increased the wireless transfer's power. Credit Courtesy of Guy Lipworth and Joshua Ensworth, graduate student researchers at Duke University Usage Restrictions None 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.