Researchers merged micro- and nano-sized networks of the same materials harnessed from seaweed to create 3D-printable gels with improved and highly controlled properties. The printed jelly could have applications in biomedical materials—think biological scaffolds for growing cells—and soft robotics. Described in the journal Nature Communications, the findings show that these water-based gels—called homocomposite hydrogels—are both strong and flexible. They are composed of alginates—chemical compounds found in seaweed and algae and commonly used as thickening agents and in wound dressings. Merging different-size scale networks of the same alginate together eliminates the fragility that can sometimes occur when differing materials are merged together in a hydrogel, says Orlin Velev, professor of chemical and biomolecular Engineering at North Carolina State University and corresponding author of the paper.