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Materials Science in Additive Manufacturing 3D printing of anti-microbial parts

(Figure S3), there would be no such surface renewal in tensile strength compared with IM parts, possibly due to
everyday use. In this regard, dead bacteria may form a the sintering method leaving about 2 vol.% voids, even
biofilm, allowing new bacteria to deposit on the debris. when the best polymers are used for the process 30,24 .
This can lead to gene transfer from the dead bacteria to the Adding rigid inorganic crystals to the surface might
living ones. Hence, the surface has to be wiped or hosed embrittle the article further and make it unusable. Hence,
to regenerate the activity. From an application perspective, PA 12 tensile bars were printed by HSS and dip-coated
this work highlights that Mg(OH) NPs are effectively with Mg(OH) crystals, and the tensile properties were
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embedded in HSS-printed articles, allowing for cleaning measured. 2
and reuse. It is also possible that if the HSS-printed articles
are steam-sterilized (a common hospital procedure for The tensile properties for the various HSS PA 12
reusable articles), the dead bacteria would be removed and bars before and after coating with Mg(OH) crystals
2
the surface regenerated for anti-microbial protection. are presented in Figure 13. While there is a decrease in
the tensile properties after coating, the reduction is not
3.6. Evaluation of the effect of dip-coating on the significant enough to compromise the usability of the
mechanical properties of PA 12 tensile bars articles. The elongation-to-break remains around 7%, well
The parts manufactured with PBF processes (HSS and above the critical threshold of 2%, which would make it
SLS) generally have a lower elongation-at-break and unusable.

Figure 12. Mechanism of formation of reactive oxygen species such as O and OH from nanoparticles. Adapted from 44
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•
2

Figure 13. Tensile properties of PA 12 control and Mg(OH) -coated PA 12 made by high-speed sintering. Tensile stress-at-break (A), modulus (B), and
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elongation at break (C).
Abbreviation: PA: Polyamide
Volume 3 Issue 4 (2024) 12 doi: 10.36922/msam.4970