Bistable mechanical linkage. (IMAGE) Proceedings of the National Academy of Sciences Caption Bistable mechanical linkage. A transition wave propagates through the entire linkage and transforms the initial straight configuration into a curved one. Credit Image courtesy of Ahmad Zareei. 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.