[n]Cycloparaphenylenes as Compatible Fluorophores for Melt Electrowriting.

Fluorescent probes are an indispensable tool in the realm of bioimaging technologies, providing valuable insights into the assessment of biomaterial integrity and structural properties. However, incorporating fluorophores into scaffolds made from melt electrowriting (MEW) poses a challenge due to the sustained, elevated temperatures that this processing technique requires. In this context, [n]cycloparaphenylenes ([n]CPPs) serve as excellent fluorophores for MEW processing with the additional benefit of customizable emissions profiles with the same excitation wavelength.

On the Stability of Electrohydrodynamic Jet Printing Using Poly(ethylene oxide) Solvent-Based Inks.

Electrohydrodynamic (EHD) jet printing of solvent-based inks or melts allows for the producing of polymeric fiber-based two- and three-dimensional structures with sub-micrometer features, with or without conductive nanoparticles or functional materials. While solvent-based inks possess great material versatility, the stability of the EHD jetting process using such inks remains a major challenge that must be overcome before this technology can be deployed beyond research laboratories. Herein, we study the parameters that affect the stability of the EHD jet printing of polyethylene oxide (PEO) patterns using solvent-based inks.

Cryo-Electrohydrodynamic Jetting of Aqueous Silk Fibroin Solutions.

The incorporation of 3D-printing principles with electrohydrodynamic (EHD) jetting provides a harmonious balance between resolution and processing speed, allowing for the creation of high-resolution centimeter-scale constructs. Typically, EHD jetting of polymer melts offers the advantage of rapid solidification, while processing polymer solutions requires solvent evaporation to transition into solid fibers, creating challenges for reliable printing. This study navigates a hybrid approach aimed at minimizing printing instabilities by combining viscous solutions and achieving rapid solidification through freezing.

Melt Electrowriting of Nylon-12 Microfibers with an Open-Source 3D Printer.

This study demonstrates how either a heated flat or cylindrical collector enables defect-free melt electrowriting (MEW) of complex geometries from high melting temperature polymers. The open-source "MEWron" printer uses nylon-12 filament and combined with a heated flat or cylindrical collector, produces well-defined fibers with diameters ranging from 33 ± 4 to 95 ± 3 µm. Processing parameters for stable jet formation and minimal defects based on COMSOL thermal modeling for hardware design are optimized.