Surface-energy ratchet mechanism (IMAGE) Doshisha University Caption The proposed ratchet mechanism utilizes the asymmetry in surface wettability between the smooth and rough faces of the teeth of a geometrically symmetric gear to achieve ratcheting motion. Credit Miku Hatatani from Doshisha University Usage Restrictions Cannot be reused without permission License Original 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.