3D nanoprinting via spatially controlled assembly and polymerization

Macroscale additive manufacturing has seen significant advances recently, but these advances are not yet realized for the bottom-up formation of nanoscale polymeric features. We describe a platform technology for creating crosslinked polymer features using rapid surface-initiated crosslinking and versatile macrocrosslinkers, delivered by a microfluidic-coupled atomic force microscope known as FluidFM. A crosslinkable polymer containing norbornene moieties is delivered to a catalyzed substrate where polymerization occurs, resulting in extremely rapid chemical curing of the delivered material. Due to the living crosslinking reaction, construction of lines and patterns with multiple layers is possible, showing quantitative material addition from each deposition in a method analogous to fused filament fabrication, but at the nanoscale. Print parameters influenced printed line dimensions, with the smallest lines being 450 nm across with a vertical layer resolution of 2 nm. This nanoscale 3D printing platform of reactive polymer materials has applications for device fabrication, optical systems and biotechnology. Additive manufacturing methods at the macroscale have seen significant advances in recent times, but advances for the bottom-up formation of nanoscale polymeric features are yet to be realized. Here, the authors demonstrate that rapid crosslinking of an AFM delivered norbornene crosslinker in presence of a surface-tethered metathesis catalysts facilitates the curing of delivered material in an extremely rapid fashion