Harvard Researchers with Transparent Speaker (image) Harvard University Share Print E-Mail Caption Jeong-Yun Sun (left) and Christoph Keplinger (right), Harvard University, demonstrate their transparent ionic speaker. It uses a signal conducted by ions, rather than electrons, to vibrate a rubber membrane. Credit Photo by Eliza Grinnell, SEAS Communications. Usage Restrictions None Share Print E-Mail 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.