Designing an Interchangeable Multi-Material Nozzle System for the Three-Dimensional Bioprinting Process

Three-dimensional bioprinting is a rapidly growing field attempting to recreate functional tissues for medical and pharmaceutical purposes. Development of functional tissue requires deposition of multiple biomaterials encapsulating multiple cell types, i.e., bio-ink necessitating switching ability between bio-inks. Existing systems use more than one print head to achieve this complex interchangeable deposition, decreasing efficiency, structural integrity, and accuracy. Therefore, the objective of this paper is to develop an alternative deposition system that will not require more than one print head for multimaterial bioprinting. To achieve that objective, we developed a nozzle system capable of switching between multiple bio-inks with continuous deposition, ensuring the minimum transition distance so that precise deposition transitioning can be achieved. This research progressed from a prototyping stage of nozzle system to the final selection of the system. Finally, the effect of rheological properties of different biomaterial compositions on the transition distance is investigated by fabricating the sample scaffolds.