Researchers in Drexel’s Department of Mechanical Engineering have developed an electrohydrodynamic (EHD) 3D inkjet printing system that uses an electric field to pull high viscosity inks to achieve high-resolution additive manufacturing.  A multi-material, multi-functional nozzle is used to print 3D objects from the high viscosity material.  High viscosity materials require high pressure and can easily clog the printing nozzle.  An air flow focusing method is used to increase printing efficiency by forming a cone-jet that does not deteriorate into a spray in an enclosed chamber.  This jet flow rate is faster than existing EHD jet printing capabilities.  The team has demonstrated proof of concept using polycaprolactone as a printing material, printing continuous lines of up to 13 micrometers and shapes in multiple layers.

Work is ongoing to analyze the effects of the operating parameters on cone-jet formation in 3D printing, material properties, and configuration of the printing head with the other 3D printing components.  The nozzle system will be optimized to accommodate different materials over a range of viscosities and jet sizes for effective material deposition.