Robust design methodologies to engineer multimaterial and multiscale bioprinters

Commonly used bioprinting technologies (e.g., material extrusion, material jetting) enable the fabrication of complex, multimaterial and multiscale scaffolds with controlled properties for tissue engineering applications. This enables the fabrication of scaffolds that more accurately replicate the structure of natural tissues. Despite the availability of commercial bioprinters, their high cost and lack of customization have driven researchers to modify existing devices or create entirely new platforms. Among all the available examples in literature, there is a strong need for more modular systems which are robustly designed taking into consideration the specific needs of bioprinting. In this context, the aim of this work is to introduce robust engineering methodologies to design and fabricate custom hardware and software for multimaterial and multiscale bioprinting. Firstly, we will identify the main design requirements that should be considered for a bioprinter (e.g., encumbrance, positioning resolution). Based on these requirements, we will then propose an analysis of the key building blocks of a bioprinter, including hardware (i.e., positioning system, toolheads, additional modules for extended functionalities), electronics (i.e., power supply, control boards), and software, introducing for each one the main concepts and equations for its optimal design. Throughout the work, we will use a customized bioprinting platform (namely, the BOOST bioprinter) as an example of the application of the proposed methodologies. Finally, we will present a validation of the methodologies and the bioprinter by fabricating high quality scaffolds through the combination of material extrusion and material jetting. The firmware developed during this work is available online as a support for developing more robust customized bioprinters.