Table 3.

Comparison of different printing technologies for gelatin towards ELS fabrication, outlining their advantages and challenges.

Printing type	Advantages	Challenges
Inkjet printing	• High resolution (5-50 μm) • High cell viability (>90%)	• Slow printing speed • Limited 3D construction ability • Limited cell density (106-107 cells mL-1) • Low viscosity of inks required (<10 mPa·s)
Extrusion printing	• High material compatibility • High structural strength • High cell densities (108-1012 cells mL-1)	• Slow printing speed • Limited resolution (50-200 μm) • High shear forces lead to low cell viability • High viscosity of inks required (>10 mPa·s) • Support required for bridge and cavity structures
DLP printing	• High resolution (20-50 μm) • Suitable for most photocurable materials	• Modification required for gelatin • Limited materials for high cell viability • Support required for bridge and cavity structures
Volumetric printing	• Fast printing speed (3-30 s) • Minimal mechanical stress on cell	• Complexity in calibration • Modification required for gelatin • Limited materials for high cell viability
Acoustic printing	• Non-contact printing	• Limited resolution • Sophisticated instrumentation
TPP	• Sub-micron resolution • High customization for complex 3D architectures	• Long fabrication time • High cost of equipment and operation • Limited throughput for large-scale structures
LIFT	• High resolution (5-50 μm) • Versatile material compatibility	• Prototype stage, limited commercial availability • Limited throughput for large-scale structures