To anyone who’s ever doubted the impact of sci-fi movies, comic books, or TV shows — hold your tongue.
Researchers from the Lawrence Livermore National Lab at the University of California, Berkeley recently unveiled a machine that is shattering the legacy of 3D printing approaches, and it was inspired by the “replicator” used in Star Trek. Instead of building objects layer by layer, the new printer constructs entire objects at once — using projected light to transform a glue-like resin into solid objects.
The advanced medical technology found in computed tomography, or CT scans, also played a role. The machine uses two-dimensional images of the product in need. A computer feeds them into a device resembling a slide projector. These images are then projected into a container filled with the resin. Dubbed Computed Axial Lithography, or CAL, the new approach involves rotating a container of this light-sensitive material while projecting into it a sequence of light patterns that range in intensity and are synchronized with the rotation — like a CT machine.
This allows a 3D pattern of energy to hit the material with more than a thousand different projections. The resin is comprised of liquid polymers mixed with photosensitive molecules and dissolved oxygen. Light activates the photosensitive compound, which depletes the oxygen. Where the energy delivered exceeds the material’s capacity, the material undergoes a chemical reaction and the part is formed.
The new approach offers two benefits and one apparent drawback. First, products that previously took hours to produce could be done in a matter of minutes. This method could also work better with flexible materials and objects — an application that the layering construct of traditional 3D printers is still looking to improve upon. The compatibility with these materials could also allow for the application of thick coatings to current items, like a new handle for a tool.
The one potential drawback is the durability of products made using this technique. The layering approach creates products that are extremely strong, yet lightweight, which has made them popular in automotive and aerospace applications.
More flexible materials, however, could be used in the medical field with objects such as implants and prosthetics.