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RESEARCH ARTICLE

Bioprinting of Multimaterials with Computer-aided

Design/Computer-aided Manufacturing

J. M. Lee, S. L. Sing, W. Y. Yeong*
Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University,
Singapore

Abstract: Multimaterials deposition, a distinct advantage in bioprinting, overcomes material’s limitation in hydrogel-based
bioprinting. Multimaterials are deposited in a build/support configuration to improve the structural integrity of three-
dimensional bioprinted construct. A combination of rapid cross-linking hydrogel has been chosen for the build/support setup.
The bioprinted construct was further chemically cross-linked to ensure a stable construct after print. This paper also proposes
a file segmentation and preparation technique to be used in bioprinting for printing freeform structures.

Keywords: Three-dimensional bioprinting, Bioprinting, Hydrogel, Three-dimensional printing, Rapid prototyping, Additive
manufacturing, Computer-aided design, Support structure generation

*Corresponding Author: W. Y. Yeong, Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang
Technological University, Singapore; wyyeong@ntu.edu.sg
Received: August 11, 2019; Accepted: January 03, 2020; Published Online: January 22, 2020

Citation: Lee JM, Sing SL, Yeong WY, 2020, Bioprinting of multimaterials with computer-aided design/computer-aided
manufacturing. Int J Bioprint, 6(1):245. DOI: 10.18063/ijb.v6i1.245.

1 Introduction addition, valves can be placed at the nozzle to
create droplets by regulating the flow of the
Bioprinting can be considered as a derivative hydrogel within the syringe .
[18]
technique that has evolved from three-
dimensional (3D) printing, also known as additive 2 Limitations of bioprinting in forming
manufacturing [1-3] . Through computer assistive structural stable construct
technology, different bioprinting techniques can
[19]
be integrated together for multimaterial printing. Hydrogels , commonly used as vehicles for
Material jetting and material extrusion are two cell delivery in bioprinting, are high water
technologies that have been commonly used in content polymers with hydrophilic polymer
bioprinting due to the ease of setup. Moreover, these chains that can be cross-linked to form 3D
[20]
processes are relatively biocompatible as opposed matrices . Naturally derived hydrogels, such
to other additive manufacturing technologies. In as collagen, gelatin, hyaluronic acid, chitosan,
material jetting bioprinting, biomaterials, cells, alginate, and cellulose, are used for tissue
and growth factors are dispensed as droplets [4-7] . engineering and in bioprinting [21-23] . However,
Comparatively, the material extrusion setup uses the naturally derived polymers have certain
a combination of an automated robotic system for drawbacks including relatively weak mechanical
controlling platform movement and a dispensing property, fast degradation, and sometimes may
system for deposition of cell-hydrogel constructs cause allergic reactions [21,23] . Materials that are
in forms of either strands or droplets [8-17] . In used for bioprinting are usually limited by their

© 2020 Lee, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License
(http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the original
work is properly cited.
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