Figure 4.

A) Design of the digitally tunable continuous multi-material extrusion bioprinter. i) Schematics and photographs showing the seven-channel printhead design connected to reservoirs that are individually actuated by programmable pneumatic valves to print microfibers of seven bioinks. ii) Images show a printed multi-component cell-laden heart-like structure. Reproduced from [180] B) Microfluidics-enabled multi-material maskless stereolithographic bioprinting. iii) The defined CFD model and the velocity profile of PEGDA in the closed microfluidic chamber under sinusoidal fluid flow. iv) The operation of the microfluidic device for consecutive injection of different bioinks. v) Schematics show the skeletal muscle tissue and tendon-to-bone insertion models, the mask for printing, and the fluorescence images of bioprinted GelMA structures containing cells of various types.[184]