Thin, Flexible and Transparent (IMAGE) University of Colorado at Boulder Caption Qingkun Liu, a postdoctoral research associate at CU Boulder, holds up samples of a new gel that could improve the energy efficiency of windows across the United States. Credit CU Boulder Usage Restrictions Credit source 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.