Design of Integrated Ring Extractor for High Resolution Electrohydrodynamic (EHD) 3D Printing

This paper presents an integrated ring extractor design in electrohydrodynamic (EHD) printing, which can overcome the standoff height limitation in the EHD printing process, and improve printing capability for 3D structures. Standoff height in EHD printing will affect printing processes and limit the height of the printed structure when the ground electrode is placed under the substrate. In this work, we designed and integrated a ground ring electrode with the printing nozzle to achieve a self-working printer head, which can start and maintain the printing process without the involvement of the substrate. We applied FEA method to model the electrostatic field distribution and strength to direct the ring extractor design, which has the similar printing capability with the system using substrate as the ground electrode. We verified the ring electrode design by experiments, and the results from experiments demonstrated a good match with results in the FEA simulation. We have characterized the printing processes using the integrated ring extractor, and successfully applied newly designed ring extractor to print polycaprolactone (PCL) 3D structures.