A clear view of hydrogel (IMAGE) Princeton University, Engineering School Caption Princeton researchers used borosilicate glass beads as a substitute for soil to study the behavior of hydrogels acting as water reservoirs in farm fields. The researchers used an additive to correct for distortion from the beads allowing them to clearly observe the hydrogel. Photo by Datta et al/Princeton University Credit Datta et al/Princeton University Usage Restrictions non-commercial use 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.