Development of a Solid Electric Propellant Microthruster

This work presents the conceptual design, modeling, and simulation of a Solid Electric Propellant Microthruster (SEPMT) intended for nanosatellite and CubeSat propulsion applications. The study focuses on the development of a MEMS-based microthruster architecture capable of delivering precise impulse for attitude control and small orbital maneuvers. The proposed system integrates a micro-fabricated combustion chamber, a thin-film resistive igniter, and a convergent–divergent micro-nozzle etched into silicon wafers. Solid energetic propellants are electrically ignited to produce high-pressure gases that expand through the microscale nozzle to generate thrust. The design enables compact integration and scalable thruster arrays suitable for miniaturized spacecraft propulsion systems. A 5×5 microthruster array configuration was developed with a total footprint of 15 mm × 15 mm. The electrical system architecture was analyzed using SPICE-based simulations to evaluate energy distribution, ignition performance, and system efficiency. Results indicate an energy delivery efficiency of approximately 87%, with an average energy consumption of about 440 mJ per thruster pulse. Computational Fluid Dynamics (CFD) simulations were performed using ANSYS Fluent to analyze compressible flow behavior within the micro-nozzle. The simulations examined pressure and velocity distributions under high-temperature gas conditions to evaluate the nozzle expansion characteristics and thrust generation capability. The proposed microthruster demonstrates an estimated thrust of approximately 461 µN per thruster with a specific impulse of about 115 seconds, suggesting potential applicability for fine attitude control and propulsion tasks in nanosatellite missions. It should be noted that this work represents an initial conceptual and simulation-based investigation of the proposed propulsion architecture. While the results provide preliminary insights into the feasibility of MEMS-based solid electric micropropulsion systems, significant further research, experimental validation, and hardware testing are required to fully verify performance, reliability, and practical implementation. Overall, the study serves as an exploratory step toward the development of compact, efficient, and scalable micropropulsion technologies for next-generation small spacecraft.