O2 Permeation (IMAGE) Shinshu University Caption This is functional group flapping mechanism in a small nanowindow which can be in an open or closed status for allowing O2 permeation. Credit Copyright 2018, <i>Nature Communications</i>, Licensed under CC BY 4.0 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.