Melt Electrowriting of Thermoplastic Elastomers

Abstract

Melt electrowriting (MEW), an additive manufacturing process, is established using polycaprolactone as the benchmark material. In this study, a thermoplastic elastomer, namely, poly(urea-siloxane), is synthesized and characterized to identify how different classes of polymers are compatible with MEW. This polyaddition polymer has reversible hydrogen bonding from the melt upon heating/cooling and highly resolved structures are achieved by MEW. The influence of applied voltage, temperature, and feeding pressure on printing outcomes behavior is optimized. Balancing these parameters, highly uniform and smooth-surfaced fibers with diameters ranging from 10 to 20 µm result. The quality of the 3D MEW scaffolds is excellent, with very accurate fiber stacking capacity-up to 50 layers with minimal defects and good fiber fusion between the layers. There is also minimal fiber sagging between the crossover points, which is a characteristic of thicker MEW scaffolds previously reported with other polymers. In summary, poly(urea-siloxane) demonstrates outstanding compatibility with the MEW process and represents a class of polymer-thermoplastic elastomers-that are, until now, untested with this approach.

Melt electrowriting of electroactive poly(vinylidene difluoride) fibers

“…To date, only six polymers, namely poly(ϵ‐caprolactone) (PCL), poly(propylene)(PP), poly(2‐ethyl‐2‐oxazoline), poly(hydroxymethyl glycolide‐ co ‐ϵ‐caprolactone), poly(urea‐siloxane) and poly(L‐lactide‐ co ‐ϵ‐caprolactone‐ co ‐acryloyl carbonate), have been shown to be processable via MEW . To successfully establish MEW for different polymers, it is typically required that a preliminary investigation is undertaken to determine the influence of the printing parameters on the fiber diameter and placement.…”

“…To date, only six polymers, namely poly( -caprolactone) (PCL), poly(propylene)(PP), poly(2-ethyl-2-oxazoline), poly (hydroxymethyl glycolide-co--caprolactone), poly(urea-siloxane) and poly(L-lactide-co--caprolactone-co-acryloyl carbonate), have been shown to be processable via MEW. [20][21][22][23][24][25] To successfully establish MEW for different polymers, it is typically required that a preliminary investigation is undertaken to determine the influence of the printing parameters on the fiber diameter and placement. Such an analysis establishes a basis for understanding the range of parameters over which the polymer can be processed, hence revealing what fiber diameters and 3D printing resolution can be achieved.…”

Melt Electrospinning of Nanofibers from Medical‐Grade Poly(ε‐Caprolactone) with a Modified Nozzle

“…Similarly some larger fibers were also observed for the empty nozzles, due to fiber pulsing [ 20 ] and fiber fusion effects. [ 21 ] This could be due to changes in the electric field due to shielding by the previously collected material or a jet instability due to pressure oscillations or charge transport. There is also a thinning of the collected material shown in the center of the stereomicroscope images in Figure 2 (yellow arrow).…”

Cells, Materials, and Fabrication Processes for Cardiac Tissue Engineering

“…Another significant limitation is the achievable 3-dimensionality, which is usually below the mm-range. The groups of Paul Dalton and Dietmar Hutmacher have spearheaded its use ( Bas et al, 2015 , 2017 ; Hochleitner et al, 2018 ) and have developed methods to increase the thickness of the MEW scaffolds to almost one cm, but again these are far from mainstream ( Wunner et al, 2018 ). The groups of Jos Malda and Joost Sluijter have been the first ones to apply MEW to cTE.…”