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The arrival of commercial bioprinters – Towards 3D bioprinting revolution!

Figure 8. Bioprinting companies around the world

many of the bioprinters operate on a Cartesian system biocompatible thermoplastics, or tissue/in vitro model
which utilizes sliding rails; this in itself is prone to specific formulations.
contamination from particles caused by friction. 2.4 Potential improvements to the current
BioBot™ Basic (ASLS) is a polar coordinate based
bioprinting system which offers a rotational stage Bioprinters-Future Design considerations
TM
movement apart from the usual 3-axis motion. Vitarix Although there has been many new bioprinting
Bioprinter (Pensées) offers a third kind of system called technologies and innovations in the field, there remain
as delta coordinate system with a circular print bed. key challenges which need to be overcome in order to
The extruders are suspended in air above the print bed realize the tissue manufacturing process. Ozbolat et
by three arms in a triangular configuration (thus the al. [109] have articulated many of such limitations with
name “delta”). This suspension arguably eliminates any different bioprinting technologies. This section discusses
contamination from particles caused by friction during additional features which may be incorporated into a
its motion. bioprinter to make the printing process faster, flexible,
The nozzle diameters across the extrusion print-heads efficient and more predictable.
vary from 50–200 microns. The printing resolution of ●Flexibility in the direction of printing: Vertical
the bioprinters primarily depends on the printing mode printing is not always desirable. For example, complex
as well the reliability of the associated motor system, neural tissues demand more skewed architecture [110] . The
but ideally it can go to as low as 1 um across all the 3 proposed solution would be engineering bioprinters with
axes. The regular extrusion-based print heads have also multiple robotic arms. In this regard, it is worthwhile to
been made possible to operate at lower temperatures note that BioAssemblyBot (ASLS), which is a 6-axis
(sub-zero, e.g., 4 deg C) and are being sold as cooled robot arm that can carry out not only additive printing
pneumatic heads. Many of the bioprinters are now but also contour printing. However, significant progress
offering a high-definition (HD) camera tool head to is still needed in terms of the ability to directly fabricate
document the work, as well to keep track of the printing using biologically relevant hydrogels, with tighter
process. Many of the companies also sell bioinks which control of the microstructure and anisotropy in 3D. A
could be natural-based, synthetic-based, sacrificial,

14 International Journal of Bioprinting (2018)–Volume 4, Issue 2