3D-printed hydrogel is soft, and sometimes it can be tough. However, could it be hard?

Here, researchers from Zhejiang University report a 3D photo-printable hard/soft switchable hydrogel composite, enabled by the phase transition (liquid/solid transition) of supercooled hydrated salt solution (solvent) within the hydrogel. This work suggests a bright future for the direct use of hard hydrogel as a robust industrial material.

When West Virginia recently banned seven artificial food dyes in products to be sold within their borders, they joined an increasing number of individual U.S. states issuing their own regulations about food manufacturing practices, allowable ingredients, or product labeling. Consequently, food manufacturers must decide how to deal with different requirements in multiple markets. A new study from the University of Illinois Urbana-Champaign examines the various ways manufacturers respond to state regulations and what drives their choices.