Effects of Electrode Design on the Melt Electrowriting of Sinusoidal Structures

Abstract

Melt electrowriting is a microscale manufacturing technique that uses polymer‐based melts to create fibrous structures. An electric field is used to stabilize a continuous molten jet, which is then written onto a substrate as a microscale fiber. Herein, it is investigated how different electrode designs affect the electric field's spatial distribution and intensity. Experiments show that the electrode design affects the temperature of the poly(ε‐caprolactone) melt in the nozzle and plays a crucial role in the formation of jet, its speed, and consequent deposition. A concave electrode design is observed to directly impact the temperature of the polymer being extruded, where it is found to be 10 and 8 °C lower than the flat and convex electrode, respectively. This lowering in temperature impacts the polymer flow and the critical translation speed directly, impacting the fidelity of prints using a sinusoidal toolpath, showing a reduction of 65% in the programmed value of amplitude. Sinusoid patterns with different amplitudes and wavelengths are designed and printed, providing a library of structures with preprogrammed mechanics for scaffold creation. A high level of control is demonstrated by designing complex alternating amplitude structures displaying dual elastic regions and step‐based mechanical properties.