Jam with the flow: Microgel-based (bio)inks that assemble during printing

Many of nature’s materials have exceptional properties because their structural organization resulted from the on-demand processing of compartmentalized materials. I want to translate this principle to extrusion-based 3D printing (EBP).

EBP is a booming fabrication approach in tissue engineering, as it provides control over material deposition in the submillimetre range in a cost-effective manner.

However, due to the many requirements for printable (bio)materials (called inks), only a limited number of chemistries can be effectively used, and typically homogeneous network compositions are obtained even though biomedical and other applications require highly controlled inhomogeneities.

Approaches providing high control over local material structure and composition are lacking.To provide a solution, I will develop a new class of microgel-based materials that jam due to the on-demand induced microgel swelling and undergo secondary crosslinking, both in the flow, resulting in a one-step printing of stable heterogeneous scaffolds with locally varying properties and compositions, relevant for mimicking real tissues.

Importantly, the approach eliminates jamming steps before printing, yields unprecedented control over local material composition and structure in the flow, down to the sub-micrometre range, and does not require post-printing crosslinking steps to stabilize the printed structures.Inspired by nature’s compartmentalized materials and supported by preliminary measurements, my microgels will serve not just as pre-defined building blocks but also as material reservoirs during printing.

The approach will be generalizable to different material systems and chemistries and, as such, holds great promise for a new generation of hydrogels and advanced inks with structural and functional properties precisely controlled during and via the printing process. This will impact fields from tissue engineering to soft robotics, agriculture, food and cosmetics.