Microrockets Moving Particles of Silica (VIDEO) University of Pennsylvania This video is under embargo. Please login to access this video. Caption Silica particles 4 mm in size can be moved in an aqueous medium without disturbing the surrounding particles. Credit Liqiang Ren Usage Restrictions Please include appropriate credits 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.