Super Expandable Foam for 3D Printing Larger Objects
Scientists from UC San Diego have developed an expandable foam that can "supersize" 3D-printed objects. They developed a foaming prepolymer resin for lithographic additive manufacturing, which can be expanded after printing to produce parts up to 40 times larger than their original volume. This allows for the fabrication of structures significantly larger than the build volume of the 3D printer that produced them. Complex geometries comprised of porous foams have applications in aerospace, energy, and biomedicine. The work was published in the American Chemical Society journal ACS Applied Nano Materials .
Transcript
00:00:06 Scientists and hobbyists alike are having fun creating customized objects with 3D printers. But a sometimes-frustrating limitation is that the object must be smaller than the 3D printer making it. Huge printers aren’t practical for making large parts because they take up lots of space and require too much time to print. Now, researchers reporting in ACS Applied Materials & Interfaces have made a new foam-like material to 3D print small objects that expand upon heating. The foam could find uses in architecture, aerospace and biomedicine. A type of 3D printing called “stereolithography” creates objects layer-by-layer. After the printer deposits each layer of light-sensitive “ink,” it exposes the material to a pre-programmed
00:00:50 pattern of light, locking the object into the desired shape. 3D printing footage of large objects. For example, I’ve seen some footage of people fastening parts together on 3D-printed prosthetic legs. Large objects can be created with specialized, expensive stereolithography machines, but they’re usually made by fastening smaller 3D-printed parts together. David Wirth, Jonathan Pokorski and colleagues at the University of California, San Diego wanted to develop an expandable resin that could be used to print large objects with an inexpensive, commercially available 3D printer. When the finished object is removed from the printer and exposed to heat, it expands, while
00:01:21 keeping its printed shape. The researchers tested many different resin formulations before they found the ideal one, which they used to 3D print a hollow, latticed sphere. Then, they heated the sphere in an oven, causing a volatile component of the resin to bubble out as a gas. This created a porous, polystyrene foam-like material that was up to 40 times larger in volume than the original printed object. With this method, the team also 3D printed other shapes, such as a boat. The original 3D-printed boat could only carry a maximum cargo of 10 grams. But the expanded boat carried up to 250 grams, or more than 25 times as much weight.
00:02:06 The researchers also made a wind turbine that could produce a small amount of electricity at its larger size. Although the new material isn’t as strong as polystyrene foam, it could someday be used for cushioning, airfoils, buoyancy aids or even expandable habitats for astronauts, the researchers say.