Additive Manufacturing Technologies for Enhancing the Development Process of Biodevices - Advanced Design and Manufacturing Technologies for Biomedical Devices - page 187

Fig. 10.11 3D scaffold for tissue engineering based on conventional woodpile structure designed
with help of a CAD program. Scale: diameter of cylinders, 200 m. Complete scaffold,

20 × 5 × 3 mm 3 (Manufactured using digital light processing: Perfactory (EnvisionTec GmbH))

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around 200 m can be obtained, although normally some unpolymerized resin

remains between piles and layers, what requires additional post-processes. In the
case of laser stereolithography, UV post-curing of around 10-20 min is common. In
the case of the structures from Figs. 10.11 and 10.12 , an additional cleaning by
compressed air was needed to extract the uncured material and obtain fi nal porous
structures, as due to capillarity the liquid uncured material could not properly fl ow
out of the structure.
Unfortunately, these prototypes are not adequate for biomedical trials, and in the
case of multilayered hollow or porous structures, we cannot either resort to the use
of rapid form/shape-copying process, for obtaining rapid molds and casting bioma-
terials, as described in Chap. 11 , due to the great number of undercuts.
However, the use of some novel additive manufacturing machines (bioplotters
and 3D printers capable of handling biomaterials, see Chap. 14 ) and the use of espe-
cially synthesized materials, as Sect. 10.6 explains, provide very adequate and
promising alternatives for further research.

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