Flexible STA possible (IMAGE) City University of Hong Kong Caption The STA can be designed to be flexible, which possesses huge potential for practical applications. Credit City University of Hong Kong Usage Restrictions Image must be used with appropriate caption and credit. 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.