3D printing never ceases to impress us. To date, 3D printing allows all kinds of objects and shapes as revealed in some articles on Substance ÉTS. Nevertheless, color is one of the major technical obstacles.
Thanks to new algorithms, engineers at the Fraunhofer Institute for Computer Graphics Research (Germany) were able to perfectly reproduce the colors of certain objects. A research that is quite promising for the future of additive manufacturing.
The result looks remarkable. In the picture above, one apple is printed in 3D but is not distinguishable from the real ones.
In a longer-term, the aim would also be to accurately reproduce biological materials such as human skin.
To get this result, researchers used Multi Jet Modeling technology (MJM) through a Stratasys Subject Connex 500 printer. This technique is equivalent to a 2D printing technique called half-toning with hundreds spray nozzels that deposit droplets of resin which are solidified by ultraviolet light. The advantage of this solution is that it offers a very fine resolution that creates the object voxel per voxel (three-dimensional pixel).
Added to this 3D printing technique is the development of algorithms capable of calculating color based on the scattering of light through further material layers. It is then possible to control very precisely the color and material of each individual voxel, as well as accounting for the translucency of the resins. This is required because most of the resins currently available have some degree of translucency to them. This means that when they are printed, the colors from within the object also play an important role in how the object is seen from the surface.
Fraunhofer Institute’s engineers have brought 3D printing to an entirely new level by creating a process that can produce more accurately colors with an incredible amount of detail. The team is optimistic about the future of this research since the results should improve as scientists develop less translucent printing materials and as printers get even higher resolution.
To learn more about the subject, you can consult the research paper entitled “Pushing the Limits of 3-D Color Printing: Error Diffusion with Translucent Materials” published on June 8, 2015 on Arxiv.