3D printers are great for rapid prototyping and building special parts with low volume, but can take a while. Today’s 3D printers could be called “3D printer”, but really, the print heads work in 2D. A 3D model is divided into hundreds of horizontal 2D planes and slowly built up in layers. This layered process can take hours or even days. What if we could print the entire model at once? A new technique that has been demonstrated by researchers from Switzerland Ecole polytechnique fédérale de Lausanne (EPFL) – and more detailed in this natural item– does just that and can print an entire model in seconds.
The new technology builds a model by curing a photosensitive resin with a laser, similar to existing stereolithography (SLA) printers. The big difference here is the application of tomographic Techniques that are also used for X-rays and ultrasound and enable rotary printing. Laser light is modulated with a DLP Chip (just like old rear projection HDTVs) and is blasted into a container full of resin. The laser covers the entire build volume and the resin container actually rotates while exposed to the light. The laser projects the model from different rotation perspectives, which are synchronized with the rotating resin, and an entire 3D model can be created in seconds.
EPFL writes: “The system is currently capable of producing two-centimeter structures with an accuracy of 80 micrometers, which is roughly the diameter of a strand of hair. However, as the team develops new devices, they should be able to do a lot to build larger objects, possibly up to 15 centimeters. “In this first public demonstration, the build volume is 16mm × 16mm × 20mm, making it one of the smallest 3D printers in the world. A resolution of 80 µm is also nothing to write home about and can be surpassed by ~ 500 $ Consumer SLA printer. However, it is very fast and the technology is just beginning.
The most common form of photosensitive resin printer is used today Stereolithography (SLA). These printers have a resin container with a window at the bottom and a DLP projector on the other side of the window. SLA printers still print one layer at a time: one building platform sinks into the resin from above and almost touches the window, leaving just enough space for a single layer of resin between the window and the building board. The DLP emits the single resin layer with the specific light pattern for this first layer, then the building platform moves up one layer, more resin flows in and another layer is projected by the DLP. A stereolithography printer cures the resin layer by layer with a 2D display, while this 3D rotary printing method cures the resin all at once with a 3D laser hologram.
Another advantage of this printing technique is that by printing an object hanging in the printing solution, no additional support structures are required. EPFL says this makes the technology a good idea for printing delicate or soft objects, including 3D bioprinting.
The researchers have a spin-off called “Ready 3D“to develop and market the technology.
Listing image from EPFL