3D-Printed, Internally Fed Electrospray Thruster

Abstract

An electrospray thruster offers several benefits as a propulsion system for small satellites, including a lower power requirement when miniaturized and a broad range of thrust and specific impulse. However, traditionally it has been manufactured through microfabrication in a cleanroom, which is both expensive and time-consuming, and is not compatible with in-space manufacturing. Advances in 3D printing technology make it possible to create microstructures at a much lower cost than microfabrication; however, internally fed electrospray thrusters have only been fabricated in a cleanroom so far, primarily due to their high hydraulic resistance requirement. In this study, this problem was approached in two ways to 3D print the internally fed electrospray thruster. The first approach was optimizing the channel design, considering 3D printing resolution and electrospray physics. The second approach was the modification of liquid resin for 3D printing to expand the lower limit on the internal channel size. The characterization of a single-emitter device showed stable emission for multiple flow rates, with current and flow rate following the well-known scaling law of electrospray in cone-jet mode. The thrust and specific impulse estimates showed that the device performance is comparable to state-of-the-art microfabricated internally fed electrospray thrusters.