3D Printing: From decimeter to µmeter?

3D printing was developed in 1984 on the principle of additivity, using a simple material-energy coupling, with stereolithography as the first technology, representing a single-photon photopolymerization process. Thanks to this principle, other processes were able to emerge, using solid, pasty, powdery, organic and/or mineral materials. However, in 1984, scientific knowledge already existed about more complex "threshold" processes that could have been exploited. If, in this case, it was possible to avoid the layer addition stage, the choice of usable materials remained more critical (and the production of metal parts could have been delayed or left in limbo...).

With transparency in mind, 3D objects can be produced without the need for superimposed layers, thanks to non-linear optical or chemical threshold processes. It is on these foundations that "volumetric" 3D printing was born (sometimes called "volumetric", no doubt because in English we speak of 3D Volumetric), consigning to oblivion the term "additive manufacturing" classically used to distinguish it from subtractive manufacturing by material removal. Volumetric 3D has a more limited range of applications than other 3D technologies, but enables objects to be produced with shorter machine and design times and, in some cases, with better spatial resolution. It should therefore become an integral part of the range of 3D devices on the market.