Effects of Electrode Design on the Melt Electrowriting of Sinusoidal Structures

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(& epsilon;-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 & DEG;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.