Adam Hadhazy, Office of Engineering Communications Feb. 18, 2021 12:59 p.m. Princeton researchers used tiny glass beads as a substitute for soil, so they could observe the behavior of hydrogels — tiny plastic blobs that can absorb a thousand times their weight in water — whose success in agriculture has been puzzlingly uneven. The researchers used a chemical that compensated for the distortion caused by the round beads, resulting in a perfectly clear view of the hydrogel. Photo by the Datta Lab, Princeton University In research that may eventually help crops survive drought, scientists at Princeton University have uncovered a key reason that mixing material called hydrogels with soil has sometimes proven disappointing for farmers.