Prototype Footwear (IMAGE) American Institute of Physics Caption The heel of this prototype winter shoe is made from a rubbery plastic embedded with tens of thousands of tiny glass fibers that protrude out of the rubber like microscopic studs to grip the ice. Credit Reza Rizvi, Yue Li, and Sharon Ravindran/ Toronto Rehabilitation Institute Usage Restrictions This image may be used only with appropriate caption and credit. 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.