TABLE 1.

Overview of (bio)printing methods for organ-on-a-chip applications.

Bioprinting method	Resolution	Materials	Cell viability issues	Costs	Other remarks
Inkjet/Droplet	Single cells	Photo-sensitive polymers and bioinks	Toxicity of the photoinitiators; Mechanical shear; Surface impact	++/+++ (50–250 k€)	Post-printing seal necessary
Extrusion	>100 µm (depends on nozzle diameter)	Polymers and bioinks (±photoinitiators)	Extrusion shear	++ (>10 k€)	Post-printing seal necessary
SLA/DLP	∼50 µm	Photo-sensitive polymers and bioinks	Toxicity of the photoinitiators	+ (0.3–1 k€)
Two photon polymerization (2PP)	<1 µm	Photo-sensitive polymers and bioinks	Toxicity of the photoinitiators	+++ (∼500 k€)	Thin glass substrates on one surface; optimization of refractive indices
Holographic	∼0.5 µm	Photo-sensitive polymers and bioinks	Toxicity of the photoinitiators	++++ (>1 M €)	Thin glass substrates on one surface; optimization of refractive indices of