3D printing has become quite advanced, however commercial printers are currently limited to printing objects smaller than the machine itself. While 3D printing of large-form objects exists, it’s usually limited to expensive, site-specific machines that are used for industrial purposes. That could change going forward thanks to new research from researchers at the University of California (UC), San Diego, who developed a material and process for printing large objects even with a low-cost and commonly available 3D printer.
Researchers used the 3D printing process known as stereolithography, which creates objects by exposing sequential layers of light-sensitive resins to patterns of light, for their work. There are two primary hurdles when using traditional printers and resins to creating large objects, said Professor Jon Pokorski, associate professor of nanoengineering at the university.
The Right Formula
After testing different resin formulas, the team developed one that could allow them to print an object that would expand to a larger size with heat, and then tested it by printing a hollow, latticed sphere. Heating the resin in an oven caused a volatile component of the material to be emitted as a gas, which created a porous, polystyrene foam-like material that was up to 40 times larger in volume than the original printed object.
The method solved both problems with printing large-scale objects with commercial printers “because the objects are printed at a small scale and expand into a much larger volume,” Pokorski told us.
However, the team was challenged as it sought to identify a “blowing agent”—or the chemical in the resin that caused it to expand--that could be used in the printing process, he acknowledged.
“These blowing agents decompose from solid or liquid to a gas generating a large volumetric expansion of the part,” Pokorski told Design News.