Device in Action (IMAGE) Duke University Caption A sample of 500 nanometer particles in solution. In the top image, the acoustic whirlpool device turned off. The bottom image shows that when the device is turned on, the nanoparticles are concentrated to the point of becoming visible as a dark line down the center of the chamber. Credit Duke University Usage Restrictions None 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.