Strain Sensor 1 (IMAGE) University of Sussex Caption Photograph of G-balls resting in a glass vial. Each ball has a soft polydimethylsiloxane (PDMS) core and is coated with microscopic sheets of graphene. Credit University of Sussex Usage Restrictions To be used only in conjunction with coverage of University of Sussex research. 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.