Xu and Guillomaitre holding solar gel (IMAGE) Princeton University, Engineering School Caption Researchers Néhémie Guillomaitre and Xiaohui Xu hold a sample of the solar absorber gel, which acts like a sponge to soak up clean water and filter out contaminants. Credit Bumper DeJesus/Princeton University Usage Restrictions Noncommercial use 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.