Prototypes 1 (IMAGE) University of Washington Caption Researchers developed a flexible pipe with an interior helical structure that enhances fluid flow in one direction, for use in applications ranging from engineering to medicine. The design mimics the shape of a shark’s intestine. This photo of eight 3D-printed prototypes shows various interior helices. Credit Ido Levin/University of Washington Usage Restrictions Must include Credit License Original 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.