Identification of optimal printing conditions for laser printing of alginate tubular constructs

Three-dimensional (3D) laser-assisted orifice-free printing technique has emerged as a promising approach for the fabrication of tissue constructs. For the better adoption of this technique, this study has investigated the effects of operating conditions, including the laser fluence and receiving substrate velocity, on the printing quality in terms of whether printed features are well-defined or not. Four main morphologies of printed lines before gelation have been identified during line printing: isolated droplets, discontinuous segments, well-defined lines, and over-printed lines. The 2125 mJ/cm2 laser fluence and 100 mm/min substrate velocity conditions, corresponding to a 0.42 overlap ratio, have been identified as a combination of optimal printing conditions by using an 8% alginate solution under a 10 Hz laser repetition rate. Alginate straight and bifurcated Y-shaped tubes have been successfully printed by applying the identified optimal printing conditions.