3D Printing: Emerging applicatives niches

The concept of 3D printing was operationalized in 1984 by two patents concerning stereolithography, consisting in the spatially resolved polymerization of a light-sensitive resin. Interested readers may wish to consult the Techniques de l'Ingénieur publications on the subject [Also available in our databases]. The coordinates of the object to be produced were stored in a computer which controlled galvanometric mirrors to transform a liquid into a solid by polymerizing a fluid layer, voxel by voxel, hence the concept of "additive manufacturing". Adding a second layer, then a third, and so on, in principle created the desired prototype part, which then had to be extracted (and washed) from the non-photototransformed fluid. Other manufacturing principles are based on the same additive principle, with processes differing essentially in the nature and methods of adhesion of the material to the object under construction. The rule of the game is to have either localized energy, or localized material positioning, or both. Additive manufacturing techniques are now well known, and offer numerous advantages.

With a continuous dynamic increase of around 20% per year, in around 35 years we have gone from centimetric dimensions to nanometric space (3D nanotechnologies), but also to the decameter (building and public works), from prototype parts with the concept of the 3D photocopier to real applications. Virtually all fields are concerned, from space, avionics, automotive and mechanical engineering to art and medical applications (3D medicines, prostheses, etc.), whenever additive manufacturing brings a decisive plus in terms of functionality and/or cost.

The aim of this article is not to analyze the various application niches that continue to develop, but to examine which areas of research may be significant for the development of additive manufacturing in the near future. Based on a situational analysis (bibliography and grey literature from internet consultation), several as yet unstabilized fields are emerging, most of them based on "hard" science (nano-micro-fabrication and micro-fluidics; 4D printing; organoids and bio-printing), but also, following the Covid-19-induced pandemic. The latter has led us to reflect on organizational openings that were ultimately not anticipated before the crisis.

In this revised version of [BM 7 970] , this axis is therefore new, and those already introduced in 2017 have been profoundly reworked in view of the...