Puckering Effect (1 of 2) (video) University of Pennsylvania Loading video... Caption The movie simulates the process of a tiny tip (with a radius of tens of nanometers, of ~ 10 nm) coming into contact and sliding on suspended elastic thin sheets (with thicknesses of one and four atomic layers respectively), such as graphene or molybdenum disulphide. Because of the attractive interactions between the two surfaces, the thinner sheet snaps on to the tip as it approaches the sample and forms a puckered region. Credit University of Pennsylvania and Science Usage Restrictions None 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.