Molecular Ruby (IMAGE) Johannes Gutenberg Universitaet Mainz Caption The molecular ruby in a solid (red) and dissolved (yellow) state can be used for contactless optical measurement of pressure. Credit photo/©: Sven Otto, JGU Usage Restrictions This image may only be used in connection with the press release "Scientists develop highly sensitive molecular optical pressure sensor", issued by Johannes Gutenberg University Mainz on July 5, 2018. 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.