Advancing scaffold biomimicry: engineering mechanics in microfiber scaffolds with independently controlled architecture using melt electrowriting

Melt electrowriting (MEW) is an additive manufacturing technique characterized by its ability to fabricate micronscale fibers from molten polymers into highly controlled 3D microfiber scaffolds. This emerging technique is gaining traction in tissue engineering and biofabrication research, however limitations in the ability to develop advanced coding to program MEW printers to fabricate scaffolds with complex fiber architectures has inhibited the development of structures with tunable and biomimetic mechanical properties. This study reports a series of non-straight scaffold architectures with combinations of independently controlled X & Y fiber spacing, corrections for MEW jet lag, and characterizations of their influences on scaffold mechanics. Polycaprolactone scaffolds with an elastic modulus ranging from 0.3 to 7.3 MPa were fabricated utilizing scaffolds manufactured from 5 layers of 55 m fibers. The inclusion of scaffold design corrections in the gcode to compensate for decreasing deposition accuracy with increasing layer height enabled us to correct for discontinuous stress-strain mechanics and improved scaffold fabrication reproducibility. This study provides a comparison between a series of highly reproducible MEW scaffold architectures with non-straight fibers compared to the common crosshatch design to inform the development of more biomimetic scaffolds applicable to a variety of clinical applications. It further illustrates the significant effect toolpath correction has on reducing poor stress-strain mechanics, therefore improving the control, reproducibility, and biomimetic capacity of the MEW technique.