Motionless Electrohydrodynamic (EHD) Printing of Biodegradable Polymer Micro Patterns

Electrohydrodynamic (EHD) jet printing creates micro or nano scale patterns using a simple configuration of a printing nozzle, precision pump, voltage generator, and pressure regulator. Drawing patterns by an EHD printing system on a substrate requires continuous and precise movement of either a printing nozzle or target substrate. This requirement for precision mechanical movement increases the setup cost and limits the spatial resolution of the printing. In this study, we propose a concept of "motionless" EHD printing that can print patterns without any mechanical motion of a printing nozzle or the substrate. The motionless EHD printing utilizes an array of target micro electrodes that can be selectively connected to a voltage generator. This study focused on the vertical and horizontal range of the motionless printing by investigating how the vertical and horizontal distances between the microelectrodes and the nozzle influenced on the quality of printing patterns. Finally, this motionless EHD printing was used to create patterns of biodegradable polymer/model drug mixtures for controlled drug delivery and their release performance in vitro was demonstrated.