SEM Image-Polycarbonate (IMAGE) U.S. Army Research Laboratory Caption Scanning electron microscopy image revealing permanent indent on the surface of polycarbonate in contrast to PUUs where no damage was observed after impact by silica micro-particles Credit U.S. Army Research Laboratory 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.