Table 1.

Bioprinting techniques for airway and lung.

Bioprinting techniques	Classification	Printability	Cell viability	Ref
Extrusion-based bioprinting	Pneumatic-based	Bioink design (rheological properties, viscoelasticity, surface tension, gelation mechanism, etc.). Bioprinting process parameters pressure, speed, temperature, nozzle parameters, and crosslinking strategies). Construct design (filament spacing and orientation).	Shear stress. Material cross-linking. Printing parameters (pressure, speed, nozzle size and shape). Characteristics of bio-ink.	Fu et al., 75 Boularaoui et al. 76
	Piston-driven
	Screw-driven
Jetting-based bioprinting	Inkjet-based bioprinting	Highly dependent on the properties of the bioink. Two important parameters (Reynolds number/Weber number—determining the ink viscosity). The influence of pressure parameters on printability. The influence of nozzle parameters on printability (nozzle size and diameter). The influence of temperature on printability.	Droplets (impact velocity, volume). Properties of bioink (Reynolds (Re) and Weber (We) numbers). Printing parameters (printing frequency, distance from nozzle to substrate). Shear stress.	Ng and Shkolnikov, 77 Ng et al.78,79
	Laser-assisted bioprinting
	Acoustic-based bioprinting
	Microvalve-based bioprinting
	Electrohydrodynamic jet bioprinting
Light-based bioprinting techniques	Digital light processing, DLP	Types of photoinitiators. Wavelength and intensity of light. Composition of bio-ink. Structural resolution.	Bioink composition (whether there are any additional protective components that can protect cells from light-induced damage).	Levato et al., 80 Fang et al., 81 Garciamendez-Mijares et al. 82
	Stereolithography, SLA
	Two-photon polymerization, 2PP