A Novel Focused Electrohydrodynamic Printing Method

The main advantages of additive manufacuring include limited waste and the ability to build complicated structures. Recently, a cost-effective, versatile method of high-resolution printing called electrohydrodynamic (EHD) printing has been introduced. This method allows for spatial resolution in the hundreds of nanometers. This process works similarly to a typical ink jetting system, except instead of the ink/polymer being pushed out of a tip, it is pulled out by an applied electric field allowing for the resultant droplet to be much smaller than the needle diameter. EHD systems are typically used in a drop-on-demand mode. Although operating in a continuous spray mode will increase throughput, its resolution is limited because of electrostatic repulsion between the drops. To overcome this limitation, we have incorporated an Einzel lens into the system to focus the droplets. To validate this approach, simulations were performed to test for different parameters, including droplet size changes and lens optimization. These parameters were then used to build a real system. This printhead system was then characterized for how well it performed. This includes comparisons of line widths of different focusing voltages.