NTU Scientists Develop Energy-Saving 'Liquid Window' (IMAGE) Nanyang Technological University Caption The smart window turns opaque when exposed to heat, thus blocking sunlight, and, when cool, returns to its original 'clear' state. Credit NTU Singapore Usage Restrictions None 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.