title: Time-Resolved Imaging Study of Jetting Dynamics during Laser Printing of Viscoelastic Alginate Solutions.
abstract: Matrix-assisted pulsed-laser evaporation direct-write (MAPLE DW) has been successfully implemented as a promising laser printing technology for various fabrication applications, in particular, three-dimensional bioprinting. Since most bioinks used in bioprinting are viscoelastic, it is of importance to understand the jetting dynamics during the laser printing of viscoelastic fluids in order to control and optimize the laser printing performance. In this study, MAPLE DW was implemented to study the jetting dynamics during the laser printing of representative viscoelastic alginate bioinks and evaluate the effects of operating conditions (e.g., laser fluence) and material properties (e.g., alginate concentration) on the jet formation performance. Through a time-resolved imaging approach, it is found that when the laser fluence increases or the alginate concentration decreases, the jetting behavior changes from no material transferring to well-defined jetting to well-defined jetting with an initial bulgy shape to jetting with a bulgy shape to pluming/splashing. For the desirable well-defined jetting regimes, as the laser fluence increases, the jet velocity and breakup length increase while the breakup time and primary droplet size decrease. As the alginate concentration increases, the jet velocity and breakup length decrease while the breakup time and primary droplet size increase. In addition, Ohnesorge, elasto-capillary, and Weber number based phase diagrams are presented to better appreciate the dependence of jetting regimes on the laser fluence and alginate concentration.
authors.affiliation: †Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, United States.
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: †Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, United States.
authors.forename: Ruitong
authors.initials: R
authors.lastname: Xiong
authors.affiliation: †Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, United States.
authors.forename: Renwei
authors.initials: R
authors.lastname: Mei
authors.affiliation: †Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, United States.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: ‡Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, United States.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Chrisey
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001672:Biocompatible Materials; D062028:Bioprinting / Q000295:instrumentation / Q000379:methods*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D007281:Ink; D007834:Lasers; D011327:Printing / Q000295:instrumentation / Q000379:methods*; D055682:Viscoelastic Substances / Q000737:chemistry*
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D006603:Hexuronic Acids; D055682:Viscoelastic Substances; D020723:Glucuronic Acid