Expandable foam for 3D printing large objects (video)

It’s a frustrating limitation of 3D printing: Printed objects must be smaller than the machine making them. Huge machines are impractical for printing large parts because they take up too much space and require excessive time to print. Now, a new material reported in ACS Applied Materials & Interfaces can be used to 3D print small objects that expand upon heating. The foam could find applications in architecture, aerospace and biomedicine.