Fractured spicule (image) Brown University Share Print E-Mail Caption The researchers found that when layered architecture is curved, cracks can propagate from layer to layer. That negates the toughness enhancement normally associated with layering in stiff biological materials. Credit Kesari Lab / Brown University Usage Restrictions None 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.