Geiger -- Water Drops (image) Northwestern University Share Print E-Mail Caption Water drops on metal nanolayer. Northwestern University and Caltech scientists have produced electricity by flowing water over extremely thin layers of inexpensive metals that have oxidized. Credit Franz Geiger, Northwestern University Usage Restrictions Credit must be given 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.