Understanding the Significance of Layer Bonding in Melt Electrowriting

This study establishes a comprehensive experimental and computational framework to quantify and control layer bonding in melt electrowriting (MEW) scaffolds. Using systematically varied processing parameters—including fiber diameter, collector distance, collector temperature, deposition delay, and print path—the authors demonstrated that layer bonding strength can vary by more than an order of magnitude and is strongly governed by polymer cooling dynamics. Small increases in fiber diameter (25 to 31 µm) or collector temperature (26 to 41 °C) drastically enhanced bond yield strength, while deposition delays caused sharp reductions due to excessive cooling. Biaxial and uniaxial testing revealed that scaffold mechanical performance is not solely dictated by geometric architecture; instead, layer bonding creates substantial variability in yield strength, stiffness, and wall height. The study further demonstrates the ability to engineer heterogeneous bond strength regions within the same scaffold and validates optical coherence tomography as a non-destructive tool to assess fused vs. unfused layers. :contentReference[oaicite:1]{index=1}