A research team led by MechSE Professors Sameh Tawfick and Randy Ewoldt, along with doctoral candidate M. Tanver Hossain and collaborators, has developed a groundbreaking embedded 3D-printing technique that enables the fabrication of ultra-fine fibers, achieving resolutions as low as 1.5 microns. Their study, recently published in Nature Communications, unlocks new possibilities for bioinspired materials and advanced engineering applications.
Nature offers countless examples of micron-scale filamentous structures, from spider silk to hagfish slime. However, traditional 3D-printing methods have struggled to replicate such fine features. Typically, 3D printing involves depositing material layer by layer in ambient air, requiring additional support structures to maintain complex shapes. Embedded 3D printing, by contrast, deposits material within a hydrogel medium, allowing intricate designs to form without additional supports. Despite its advantages, previous embedded 3D-printing techniques faced limitations when printing fibers below 16 microns, as surface tension caused filaments to break before they could solidify.
To overcome this, the researchers employed a solvent exchange method that enabled immediate curing of the ink upon deposition, preventing filament snapping. This innovative approach resulted in a resolution of 1.5 microns—far surpassing previous limits. Additionally, the team developed a multi-nozzle system to enhance manufacturing speed.
The breakthrough holds promise for mimicking nature’s fiber-based structures, including those found in hagfish slime, which combines superior mechanical properties with flexibility. Ewoldt, who has studied hagfish slime for over a decade with collaborator Professor Douglas Fudge of Chapman University, sees the new technique as a step toward replicating nature’s remarkable materials.
The ability to produce ultra-fine fibers has significant implications across various fields. Bioinspired materials could revolutionize soft robotics, textiles, and medical applications. Additionally, semiconductor manufacturing could benefit from this high-resolution printing technique, enabling the fabrication of microstructures that conventional methods cannot achieve.
“This research overcomes a long-standing limitation of 3D printing—producing soft materials with diameters as small as one micron,” said first author Dr. Wonsik Eom, now a faculty member at Dankook University. “Achieving this level of precision lays the foundation for mimicking microfibers and hair-like structures with advanced functionalities.”
Tawfick emphasized the versatility of the approach, stating, “This method allows us to produce complex 3D hairs with fine diameters using an ultraprecise 3D printer.” Looking ahead, the team aims to combine ultra-fine fibers with functional materials to create innovative biomimetic structures, further expanding the frontiers of advanced materials science and engineering.
