Open-source syringe extrusion head for shear-thinning materials 3D printing

Purpose: This article reports the development of an open-source syringe extrusion head for shear-thinning materials, aiming to adapt open-source 3D printers to be helpful in research lines that use gels, hydrogels, pastes, inks, and bio-inks. Design/methodology/approach: This hardware was designed to be compatible with a Graber i3-based 3D printer; nevertheless, it can be easily adapted to other open-source 3D printers.

Findings: The extrusion head successfully deposits the material during the 3D printing process. It was validated fabricating geometries that include scaffold structures, which are a possible application of bioprinting for tissue engineering. As reported, the extruded filaments allowed the porous samples' structuration.

Practical implications: This system expands the applications of open-source 3D printers used at the laboratory scale. It enables low-cost access to research areas such as tissue engineering and biofabrication, energy storage devices, and food 3D printing. Originality: The open-source hardware here reported is of simple fabrication, assembly, and installation.

It uses a Cardan coupling and a three guides system to transfer the stepper motor motion. This approach allows continuous movement transfer to the syringe piston, producing an adequate deposition or retraction. Thus, the effect of misalignments is avoided, considering that these latter can cause skipping steps in the motor, directly affecting the deposition.