3D Printing an Ion Propulsion System

As much as we love Star Trek, we have to admit there are some continuity problems. For example, in Spock’s Brain, the alien-of-the-week’s ion drive gave Scotty engineering envy. However, in The Menagerie, the computer identifies a Starfleet shuttlecraft as having ion propulsion. Either way, ion propulsion is real and NASA has toyed with it for ages and many satellites use it for maintaining orbit. Now researchers from MIT and the Monterrey Institute of Technology and Higher Studies 3D printed tiny ion engines.

The engine is about the size of a dime and, like all ion engines, produces tiny amounts of thrust. In fact, the researchers liken it to half the weight of one sesame seed from a hamburger bun. However, in space, these tiny thrusts add up and over time can produce significant acceleration.

The full paper is available and shows the device operates electrohydrodynamically, creating a fine spray of charged particles. Interestingly, the device is capable of creating fine sprays of liquid or nanofibers, so the applications aren’t just for space vehicles. However, the researchers were actually surprised that the device creates a pure ion jet and they aren’t entirely sure how the device works.

The device has a reservoir of liquid with an array of emitter cones. The cones are coated with zinc oxide nanowires that act as wicks to transfer the liquid to the emitter tips where the liquid is ionized and expelled. The researchers think the nanowires are responsible for the creation of the pure jet of ions.

An ion-powered spacecraft is visiting Mercury. The ion drive we really want to see, though, is on our very own pedal-driven space bike.