Plectoneme (image) Harvard John A. Paulson School of Engineering and Applied Sciences Share Print E-Mail Caption A filament is clamped at the top end and prestretched by a small amount by applying a downward axial load to the bottom end. The bottom end is then twisted, keeping the axial load on the bottom end constant. After a critical amount of twist is inserted, the filament spontaneously buckles into a loopy. Credit (Video courtesy of Nicholas Charles/Harvard SEAS) Usage Restrictions with credit 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.