In a groundbreaking advancement in space engineering, researchers at the Massachusetts Institute of Technology (MIT) have unveiled the world’s first fully 3D-printed electrospray engine capable of emitting droplets for propulsion. This innovative engine promises to revolutionize the field of small satellite technology, particularly for CubeSats that serve in academic research and other applications. Unlike traditional thrusters that rely on costly and time-intensive fabrication processes, this novel device can be produced at a significantly lower cost and with remarkable speed. Utilizing commercially available 3D printing materials, the technology pushes the boundaries of what’s possible in space propulsion systems.
Electrospray engines work by applying an electric field to conductive liquids, producing a high-speed jet of ultra-fine droplets. This method can generate thrust for small spacecraft while using propellant far more efficiently than conventional chemical rockets, particularly during precise in-orbit maneuvers. In the world of propulsion engineering, where minute adjustments can mean the difference between success and failure in missions, the ability to fine-tune propulsion systems is invaluable.
However, one of the fundamental challenges in developing electrospray engines has been their multifaceted construction. Traditionally, these engines have demanded sophisticated semiconductor manufacturing techniques that not only require specialized cleanrooms but also limit accessibility and scalability. The MIT team set out to overcome these hurdles by demonstrating a 3D-printed solution that successfully integrates multiple functionalities into a streamlined device that can potentially be manufactured right in space.
The researchers devised a modular manufacturing method that combines two distinct types of 3D printing technologies, addressing the difficulty of creating a hybrid electrospray engine with both macro and microscale components. This innovative dual-tech approach involves utilizing vat photo polymerization printing (VPP) methods to achieve unprecedented levels of precision and performance.
Their prototype comprises 32 electrospray emitters working in concert to create a steady and consistent flow of propellant. This modular design not only generates as much thrust as existing models but can also be fabricated more cost-effectively. Imagine the possibility of astronauts printing these engines on-site, reducing the need for supply missions from Earth—a monumental step towards sustainable exploration.
In constructing the engine, the MIT team focused on the importance of scalability in fabrication. An electrospray engine relies on a reservoir of propellant that must navigate microfluidic channels to reach each emitter. Sharp emitter tips are critical for the engine’s ability to produce thrust efficiently at low voltages, and the intricate hydraulic systems required to manage the flow of propellant are complex to engineer.
The emitter array within the design is an assembly of eight modules, each containing four emitters. For optimal performance, these modules must function in unison, necessitating precise alignment and integration. Velásquez-García, a senior author of the study, emphasized in his statements the importance of blending different additive manufacturing techniques to achieve high-performance outputs, with each technology excelling at a particular scale.
To achieve this, the research team employed two complementary VPP techniques. The first, known as two-photon printing, leverages a finely focused laser to cure resin in specifically defined zones. This allows for intricate designs with sharply defined edges, crucial for the fabrication of pointed emitter tips necessary for efficient droplet ejection. However, constructing the broader manifold block housing for the emitter modules demanded the use of another technology: digital light processing. This alternate method engages a projector to solidify layers of resin progressively, enabling the large structure to be built with greater speed and structural fidelity.
While the technical accomplishments of this engine are impressive, equally essential was the consideration of the materials used in the printing process. The researchers undertook rigorous chemical tests to ensure that their printing materials were compatible with the conductive liquid propellant. Compatibility is critical for the engine’s operational lifespan, as corrosive issues or material degradation could radically undermine the performance or reliability of the thruster.
In tests, the 3D-printed prototype demonstrated the ability to generate thrust efficiently—outperforming not only existing electrospray engines but also larger, more expensive chemical rockets. Adjustments in the pressure of the propellant and modulation of voltage have shown promising results for optimizing performance without the cumbersome networks traditionally required for fluid control. By simplifying the thruster’s design, the team has delivered a more lightweight and less expensive solution that enhances propulsion efficiency.
Furthermore, Velásquez-García hinted at exciting avenues for future exploration, encouraging further studies into voltage modulation at various thresholds and intricate designs involving denser arrays of emitter modules. The ultimate aim is to see this innovative technology fully operational on a CubeSat mission, showcasing the practicality of a fully 3D-printed propulsion system working in concert within a spacecraft’s operational dynamics.
Looking ahead, the implications of this technology extend beyond merely creating propulsion systems. As humanity ventures deeper into the final frontier, developing in-space manufacturing capabilities will be vital. The prospect that astronauts can construct their propulsion systems on demand—dramatically reducing reliance on Earth-bound supply chains—could set a new standard for future missions.
This multidisciplinary effort encapsulates the intersection of engineering, materials science, and space exploration. The research reinforces the growing recognition that 3D printing is not merely a manufacturing convenience but a transformative technology with the potential to shape the next generation of aerospace solutions and strategies.
In conclusion, the creation of the first fully 3D-printed, droplet-emitting electrospray engine marks a paradigm shift in satellite propulsion. The benefits of cost efficiency, rapid production, and operational effectiveness underscore the importance of this research. As we endeavor to democratize access to space technologies, this innovation positions MIT at the forefront of pioneering achievements that will impact the future of space exploration for years to come.
Subject of Research: Electrospray Engine Technology
Article Title: High-Impulse, Modular, 3D-Printed CubeSat Electrospray Thrusters Throttleable via Pressure and Voltage Control
News Publication Date: 11-Feb-2025
Web References: Advanced Science Journal
References: doi:10.1002/advs.202413706
Image Credits: Credit: Courtesy of the researchers
Keywords
Electrospray Engine, 3D Printing, CubeSat, Space Propulsion, MIT Research, Microfluidics, Additive Manufacturing, Space Exploration, Aerospace Engineering, Advanced Materials.
