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Originally from a small village in France near St-Etienne, I went to Toulouse to study material science at an engineering school : the ENSIACET. Here I discovered several new technologies, including the additive manufacturing that provides an innovative solution to the production of objects with complex shapes. I also got the opportunity to do an internship abroad and I went to the UK and worked in a health care company. That’s where my interest in biomaterials came from.

So, after this experience I started a PhD in belgium at the BCRC on the optimisation of the stereolithography process applied to β-tricalcium phosphate (β-TCP) bioceramics. This was an opportunity to combine biomaterials with an additive manufacturing technology. The β-TCP was chosen for its biological properties. Indeed this material is biocompatible and also biodegradable therefore, used as a bone implants it can help the natural remodelling process of the bone. The idea of this PhD project was to understand the whole process : from the preparation of the suspensions needed for the stereolithography, to the printing of the parts and the post treatments in order to obtain dense bioceramic parts, with the goal to produce bone implants in the futur.

Considering that the stereolithography process is an additive manufacturing technology based on the photopolymerisation of a resin, the first step of the project was to find the right monomers to prepare the photosensitive resin. The first parameters to consider were the reactivity of the monomers and their rheological behaviour but then, the next challenge was to mix the prepared resin with the bioceramic powder and, as a dispersant was necessary, the compatibility between the monomers and the dispersant was also important. Finally, several mixing techniques were studied and a SpeedMixer providing a dual centrifugation force was found to enable the fast preparation of homogenous suspensions. This is were the printing tests began, and after a lot of trials it was eventually possible to find the right parameters to print parts with a density above 98%.

The last steps were the optimisation of the post-treatment steps and the characterisation of the parts. This gave me the opportunity to work with the CER group in order to evaluate the biological properties of the printed parts. And I also collaborated with the UPHF to study alternative ways to debind and sinter the printed parts. The preliminary tests gave encouraging results : the parts had adequate biological properties, meaning that the stereolithography process and the use of a photosensitive resin did not impact the properties of the β-TCP, and the microwave technology showed its potential to speed up the debinding and sintering steps.

However, there is still a lot of work to be done in order to be able to print quickly bone implants with this technology, but my PhD as come to an end. Nethertheless, it was a great experience and I learned a lot. I also got the opportunity to travel to conferences and to present my work, I even participated in the ECerS student speech contest this year and won the 3rd place ! Finally, I’m very grateful for the Doc3D Printing network, of which my PhD was part of, that enabled me to meet other PhD students, to work with them and to share with them throughout these 3 years of PhD !

Chloé Goutagny

Belgian Ceramic Research Centre

chloegoutagny@gmail.com