Researchers from the University of San Diego have developed a polystyrene foam-like material that could allow the 3D printing of objects 40 times larger in volume than the original printed object.

Typically, 3D printed objects must be smaller than the machine making them. Huge additive manufacturing machines are impractical for printing of large parts because they take up too much space and require excessive time to print.

Stereolithography machines — which use sequential layers of light sensitive resigns to patterns of light — can make large objects made by fastening smaller 3D-printed components together.

The foam material created by USD could be used to print large objects for applications in architecture, aerospace and biomedicine.

The resin of the experimental foam can be printed small but when exposed to heat, expand to a larger size. The researchers used the formulation to 3D print a hollow, latticed sphere and when the sphere is heated in an oven, it causes the component in the resin to bubble out as a gas allowing it to grow to 40 times larger in volume than the original printed object.

Researchers said the foam could be used to 3D print shapes as large as a boat, which could carry about 20 times more weight or a wind turbine that could produce a small amount of electricity at its larger size.

While the material is not as strong as polystyrene foam, it could someday be used for cushioning, airfoils, buoyancy aids or even expandable habitats for astronauts.

The full research can be found in the journal Applied Materials and Interfaces.