Multi-walled Carbon Nanotube (IMAGE) Rensselaer Polytechnic Institute Caption A multi-walled carbon nanotube partly filled with an iron carbide nanowire. Credit Johannes Gutenberg University/Banhart 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.