Page 17 - IJB-7-1

Zhang, et al.
A B

Figure 4. Bio-composite printing assisted by non-contact field regulation technology. (A) The ultrasonic-assisted extrusion printing with the
capacity of no-contact cell arrangement based on the acoustophoretic principle (from ref. licensed under Creative Commons Attribution
[66]
4.0 license). (B) The extrusion printing system combined with the external magnetic field and material component mixing printhead for
adjusting the material concentration and particle orientation during printing procedure (from ref. licensed under Creative Commons
[68]
Attribution 4.0 license).

products; Skeinforge, an open-source program composed to prepare a multi-nozzle extrusion printing platform
of Python scripts that can convert 3D models into G-Code that is suitable for 3D printing of various materials .
[70]
files. Focusing on the needs of medical applications, the The NovoGen MMX bioprinter of Organovo has two
Magics developed by Materialise is the most representative printheads for printing cell-laden materials and cell-free
program, as Magics can process not only the CAD model materials. Two vials housed on the instrument can adjust
generated through 3D model reconstruction by Mimics the temperature of materials. Besides, the device is also
but also the general CAD data output by the CAD/Re equipped with a laser calibration device to calibrate the
software system. The generated model files by Magics position of the micropipette . Whatley et al. developed
[71]
are saved in STL format and can be fabricated by a rapid a 3D additive manufacturing equipment to prepare the
prototyping machine. biomimetic elastic intervertebral disk scaffold . The
[72]
With the continuous improvement in 3D bioprinting system of RegenHU uses air pressure for
biomanufacturing and 3D bioprinting technology, the the extrusion of materials to satisfy the requirements of
application field has also expanded from the preparation biological fabrication. The printer has strong adaptability
of biological scaffolds to cell printing, cell assembly, and is easy to operate. The inlet air pressure can be
construction of complex biological structures, etc., which adjusted according to different viscosity of the materials
make the technical route based on industrial 3D printers so that the fabrication of bioconstruct consisting of multi-
no longer meet the demand. Many research institutions materials can be carried out. The 3D-Bioplotter printing
develop corresponding bio-CAD/CAM/3D printing platform of EnvisionTec has high mobile precision and
systems for specific bioprinting processes. Shim et al. multiple printheads. The printheads have embedded
combined air pressure extrusion with piston extrusion heating modules and can be swiftly changed. A high-

International Journal of Bioprinting (2021)–Volume 7, Issue 1 13