Study of the Graphene Energy Absorbing Layer and the Viscosity of Sodium Alginate in Laser-Induced-Forward-Transfer (LIFT) Bioprinting

Abstract

Abstract Laser induced forward transfer (LIFT) bioprinting has been viewed as a new and actively developed three-dimensional bioprinting technology due to its high accuracy and good cell viability. The printing quality is highly dependent on the jet formation and its stability in the LIFT bioprinting process. The objective of this study is to investigate the effect of a graphene Energy Absorbing Layer (EAL) and alginate hydrogel (SA) (w.t. 1% and 2%) viscosity on jet generation in the LIFT bioprinting process. Since SA exhibits a shear-thinning behavior, it is a non-Newtonian fluid. The effect of EAL thickness and SA’s viscosity were addressed for various experimental conditions. After the laser irradiated on the quartz substrate, small holes caused by laser interaction appeared in the interaction area on the EAL. The EAL substrate with multiple holes was examined using an optical microscope, and the morphology of holes was observed and compared. The images of jet generation showed that graphene EAL can assist in the transfer of SA with a low laser energy absorption rate. The viscosity of the SA also plays a significant role in the generation of a stable jet for SA transfer. For the cases with the same laser energy input, the jet generated using higher viscosity bioink had a smaller initial velocity, which eventually led to a shorter jet length. The findings in this study will facilitate the development of new EAL in LIFT bioprinting.