MIT researchers have developed their first fully 3D-printed electrospray engine, a breakthrough that could make satellite propulsion more accessible and cost-effective.
The new technology, created by engineers at the Massachusetts Institute of Technology (MIT), offers a streamlined approach to producing electrospray thrusters, which are used to propel small satellites, such as CubeSats, in space.
Unlike traditional methods that rely on expensive and time-consuming semiconductor cleanroom fabrication, the MIT-designed thruster can be manufactured rapidly using commercially available 3D printing materials and techniques, as reported in a news release.
Electrospray engines generate thrust by applying an electric field to a conductive liquid, producing a high-speed jet of tiny charged droplets.
While the thrust from an individual emitter is small, these engines typically operate arrays of emitters in parallel to produce sufficient force for precise in-orbit maneuvers.
The MIT team’s fully 3D-printed device consists of 32 electrospray emitters and has demonstrated performance comparable to or better than existing droplet-emitting electrospray engines.
The ability to 3D-print these thrusters in orbit could allow astronauts to manufacture propulsion systems on demand, reducing dependence on Earth-based supply chains.
“Using semiconductor manufacturing doesn’t match up with the idea of low-cost access to space,” said Luis Fernando Velásquez-García, a principal research scientist in MIT’s Microsystems Technology Laboratories (MTL) and senior author of the study.
“We want to democratize space hardware. In this work, we are proposing a way to make high-performance hardware with manufacturing techniques that are available to more players.”
The MIT researchers employed a modular approach that combined two different types of vat photopolymerization printing (VPP), a method that uses light to solidify a photosensitive resin into 3D structures.
For the finely detailed emitter modules, they used two-photon printing, a technique that enables ultra-precise fabrication of sharp emitter tips and narrow capillaries for propellant flow.
The larger manifold block, which houses the emitters and distributes the liquid propellant, was produced using digital light processing, a higher-throughput VPP technique.
By combining these methods, the team created a scalable manufacturing process that maintains the structural integrity and performance of the thruster.
In addition to 3D printing the components, the researchers conducted chemical experiments to ensure the printing materials were compatible with the conductive liquid propellant.
They also developed a method to assemble the thruster in a way that prevents misalignment and leakage, which could compromise its long-term performance.
Their prototype demonstrated greater efficiency than traditional chemical rockets and surpassed the performance of existing electrospray thrusters.
The study also explored how different operational parameters influenced performance. The researchers found that adjusting the applied voltage, rather than modifying the propellant pressure, provided greater control over thrust generation.
This finding suggests that a simplified design without complex pipes, valves, or pressure controls could enhance efficiency while reducing weight and cost.
“We were able to show that a simpler thruster can achieve better results,” Velásquez-García said.
Looking ahead, the MIT team aims to refine their design by increasing the density and size of the emitter arrays.
They also plan to explore multiple electrode configurations to enhance control over the propulsion process.
Ultimately, they hope to demonstrate a CubeSat using a fully 3D-printed electrospray engine for both orbital maneuvering and deorbiting.
This research, published in Advanced Science, was supported by a MathWorks fellowship and the NewSat Project and was conducted in part using MIT.nano facilities.
