Self-Healing Reverse Filter (VIDEO) Penn State This video is under embargo. Please login to access this video. Caption Self-healing reverse filters allow large particles through but restrict smaller particles. Credit Birgitt Boschitsch, Penn State Usage Restrictions non commercial use only 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.