Fragile Topology (image) Princeton University Share Print E-Mail Caption Remarkable materials known as topological insulators have a fragile side. Credit Image courtesy of Zhi-Da Song, Princeton University. Usage Restrictions Image courtesy of Zhi-Da Song, Princeton University. 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.