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International Journal of Bioprinting Bioprinting for wearable tech and robot

of several factors, such as their chemical composition 2.3.2. Microfluidic systems
that directly affects bioactivity and resorption rates. The Microfluidics refers to the science and technology of
manufacturing process also affects material properties. systems that process or manipulate small amounts of fluids
Moreover, the structural integrity and resolution of using microscale channels. The interdisciplinary aspects of
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the printed objects should be optimized to accurately microfluidics enable the precise control and manipulation
replicate the complex internal architectures for effective of fluidic environments for various applications, including
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biological integration. 55 bioprinting. Additionally, microfluidic systems have been
employed as delivery systems to facilitate the precise and
The correlation between materials, bioprinting
methods, and their corresponding biomedical applications controlled transport of biomaterials to the printhead of the
bioprinter for subsequent layer-by-layer fabrication of 3D
is presented in Table 1.
biological tissues. Further applications of microfluidics in
2.3. Machinery bioprinting include the development of gradient materials,
Compared to conventional additive manufacturing where different types of cells or growth factors are precisely
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equipment, bioprinters require optimization to ensure positioned within the printed structure. These gradients
cell viability and function while meeting the demands are essential for mimicking the natural composition of
for precise and rapid fabrication. Apart from the various tissues, where multiple cell types coexist in a spatially
bioprinting techniques (Section 2.1), crosslinking and organized manner. Microfluidic channels can be designed
microfluidic systems are also commonly used as hardware to combine different bioinks in predefined ratios before
for constructing biological structures. deposition, enabling seamless integration of different
materials within a single printed construct. Additionally,
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2.3.1. Bioprinters microfluidics can be explored for its potential in on-chip
The evolution of bioprinting technology from basic designs bioprinting, which holds significant potential in developing
to advanced, intelligent systems highlights a significant implantable medical devices. 76
technological trajectory. Extrusion-based bioprinters
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offer a basic yet effective approach for depositing bioinks 2.3.3. Intelligent control
in a layer-by-layer manner. Inkjet bioprinters complement Intelligent algorithms can be used to tune the motions of
extrusion-based bioprinters by providing higher resolution the bioprinter. By synchronizing the movement of multiple
patterns but face limitations with viscous materials. SLA- printheads and modulating printing parameters (e.g.,
based printers are known for their capability to achieve speed, pressure, and pathway) in real-time, these systems
fine resolution and print complex geometries by curing can accommodate the variable behaviors of various bioinks.
photosensitive resins with ultraviolet (UV) light, suitable Among the intelligent methods, machine vision
for fabricating intricate tissue scaffolds. The capabilities algorithms, including convolutional, transformer, and
of commercial bioprinters have transformed from basic graph neural networks, can be integrated into printers to
mechanical deposition to sophisticated integrated systems enable real-time monitoring and precise process control. 77,78
endowed with intelligent features. Bioprinters integrated By continuously capturing high-resolution images of
with automation, sophisticated software, and feedback the bioprinted structures during the printing operation,
systems enable real-time adjustments during the printing these systems provide valuable feedback on the accuracy
process. These advancements highlight the increasingly of bioink deposition, supplemented with automatic
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complex applications in the field of medical science. Some adjustments of the motion path, speed, and material flow
of these commercial 3D bioprinters are illustrated in Table 2. rate. Dynamic corrections using machine vision-based

Table 1. Materials used for different bioprinting techniques and applications.
Material Bioprinting technique Applications

Cells and extracellular matrix Inkjet ; extrusion 57,58 Bone ; liver ; glands 58
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57
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components
59
Hydrogels Extrusion 59,60 ; inkjet ; laser 62 Cartilage ; neural ; microsphere ; Y-shaped vessel 62
61
60
61
Polymers Extrusion ; stereolithography (SLA) 64 Cornea 63,64
63
65
66
Nanocomposites Extrusion 65,66 ; SLA 67 Muscle ; cardiovascular ; heart 67
Bioactive materials Extrusion ; SLA 69 Skin ; brain 69
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Volume 10 Issue 6 (2024) 21 doi: 10.36922/ijb.3590