Until now, the size of 3D-printed objects has been limited by the size of 3D printers. In most cases, in order to produce large items used in, say, aerospace, manufactures have had to fasten, weld or glue smaller 3D-printed substructures together. But that might change soon. A team from UC San Diego developed a foaming resin that can expand to up to 40 times its original volume. 

The expandable resin allows objects to be printed and then grow to their final size. The researchers believe this could be especially useful in fields like architecture, aerospace, energy and biomedicine. The lightweight foam could also be used in floatation devices.